diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/LSMTreeOperatorTestHelper.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/LSMTreeOperatorTestHelper.java
index 80b5285..f257b46 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/LSMTreeOperatorTestHelper.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/LSMTreeOperatorTestHelper.java
@@ -21,13 +21,20 @@
 
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
+import edu.uci.ics.hyracks.test.support.TestVirtualBufferCacheProvider;
 
 public class LSMTreeOperatorTestHelper extends TreeOperatorTestHelper {
-
+    protected static int DEFAULT_MEM_PAGE_SIZE = 32768;
+    protected static int DEFAULT_MEM_NUM_PAGES = 1000;
+    protected static double DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE = 0.01;
     protected final IOManager ioManager;
+    protected final IVirtualBufferCacheProvider virtualBufferCacheProvider;
 
     public LSMTreeOperatorTestHelper(IOManager ioManager) {
         this.ioManager = ioManager;
+        this.virtualBufferCacheProvider = new TestVirtualBufferCacheProvider(DEFAULT_MEM_PAGE_SIZE,
+                DEFAULT_MEM_NUM_PAGES);
     }
 
     public String getPrimaryIndexName() {
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/TreeOperatorTestHelper.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/TreeOperatorTestHelper.java
index 932e166..362badb 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/TreeOperatorTestHelper.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/common/TreeOperatorTestHelper.java
@@ -23,9 +23,6 @@
 
     protected final SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
     protected final String sep = System.getProperty("file.separator");
-    protected static int DEFAULT_MEM_PAGE_SIZE = 32768;
-    protected static int DEFAULT_MEM_NUM_PAGES = 1000;
-    protected static double DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE = 0.01;
 
     public String getPrimaryIndexName() {
         return System.getProperty("java.io.tmpdir") + sep + "primary" + simpleDateFormat.format(new Date());
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/AbstractfWordInvertedIndexTest.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/AbstractfWordInvertedIndexTest.java
index 808afac..cd3cda7 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/AbstractfWordInvertedIndexTest.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/AbstractfWordInvertedIndexTest.java
@@ -57,6 +57,7 @@
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexBulkLoadOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.TreeIndexCreateOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallbackFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexSearchModifierFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.BinaryTokenizerOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.dataflow.LSMInvertedIndexBulkLoadOperatorDescriptor;
@@ -73,6 +74,7 @@
 import edu.uci.ics.hyracks.test.support.TestIndexLifecycleManagerProvider;
 import edu.uci.ics.hyracks.test.support.TestStorageManagerComponentHolder;
 import edu.uci.ics.hyracks.test.support.TestStorageManagerInterface;
+import edu.uci.ics.hyracks.test.support.TestVirtualBufferCacheProvider;
 import edu.uci.ics.hyracks.tests.integration.AbstractIntegrationTest;
 
 @SuppressWarnings("rawtypes")
@@ -83,6 +85,8 @@
 
     protected static final int MERGE_THRESHOLD = 3;
 
+    protected IVirtualBufferCacheProvider virtualBufferCacheProvider = new TestVirtualBufferCacheProvider(
+            DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES);
     protected IStorageManagerInterface storageManager = new TestStorageManagerInterface();
     protected IIndexLifecycleManagerProvider lcManagerProvider = new TestIndexLifecycleManagerProvider();
     protected IIndexDataflowHelperFactory btreeDataflowHelperFactory = new BTreeDataflowHelperFactory();
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/PartitionedWordInvertedIndexTest.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/PartitionedWordInvertedIndexTest.java
index dfd5495..2038171 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/PartitionedWordInvertedIndexTest.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/PartitionedWordInvertedIndexTest.java
@@ -52,9 +52,9 @@
                 PointableBinaryComparatorFactory.of(IntegerPointable.FACTORY) };
 
         invertedIndexDataflowHelperFactory = new PartitionedLSMInvertedIndexDataflowHelperFactory(
-                new ConstantMergePolicyProvider(MERGE_THRESHOLD), ThreadCountingOperationTrackerFactory.INSTANCE,
-                SynchronousSchedulerProvider.INSTANCE, NoOpIOOperationCallback.INSTANCE, DEFAULT_MEM_PAGE_SIZE,
-                DEFAULT_MEM_NUM_PAGES, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE);
+                virtualBufferCacheProvider, new ConstantMergePolicyProvider(MERGE_THRESHOLD),
+                ThreadCountingOperationTrackerFactory.INSTANCE, SynchronousSchedulerProvider.INSTANCE,
+                NoOpIOOperationCallback.INSTANCE, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE);
     }
 
     @Override
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
index 9e5a47b..8e5aa6f 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/invertedindex/WordInvertedIndexTest.java
@@ -46,10 +46,10 @@
                 PointableBinaryComparatorFactory.of(UTF8StringPointable.FACTORY),
                 PointableBinaryComparatorFactory.of(IntegerPointable.FACTORY) };
 
-        invertedIndexDataflowHelperFactory = new LSMInvertedIndexDataflowHelperFactory(new ConstantMergePolicyProvider(
-                MERGE_THRESHOLD), ThreadCountingOperationTrackerFactory.INSTANCE,
-                SynchronousSchedulerProvider.INSTANCE, NoOpIOOperationCallback.INSTANCE, DEFAULT_MEM_PAGE_SIZE,
-                DEFAULT_MEM_NUM_PAGES, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE);
+        invertedIndexDataflowHelperFactory = new LSMInvertedIndexDataflowHelperFactory(virtualBufferCacheProvider,
+                new ConstantMergePolicyProvider(MERGE_THRESHOLD), ThreadCountingOperationTrackerFactory.INSTANCE,
+                SynchronousSchedulerProvider.INSTANCE, NoOpIOOperationCallback.INSTANCE,
+                DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE);
     }
 
     @Override
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java
index c67cbfd..fa32dce 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/btree/LSMBTreeOperatorTestHelper.java
@@ -33,9 +33,9 @@
     }
 
     public IIndexDataflowHelperFactory createDataFlowHelperFactory() {
-        return new LSMBTreeDataflowHelperFactory(new ConstantMergePolicyProvider(MERGE_THRESHOLD),
-                ThreadCountingOperationTrackerFactory.INSTANCE, SynchronousSchedulerProvider.INSTANCE,
-                NoOpIOOperationCallback.INSTANCE, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES,
+        return new LSMBTreeDataflowHelperFactory(virtualBufferCacheProvider, new ConstantMergePolicyProvider(
+                MERGE_THRESHOLD), ThreadCountingOperationTrackerFactory.INSTANCE,
+                SynchronousSchedulerProvider.INSTANCE, NoOpIOOperationCallback.INSTANCE,
                 DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE);
     }
 
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java
index a892b4e..9da48a0 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeOperatorTestHelper.java
@@ -40,8 +40,8 @@
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             IBinaryComparatorFactory[] btreeComparatorFactories, ILinearizeComparatorFactory linearizerCmpFactory) {
         return new LSMRTreeDataflowHelperFactory(valueProviderFactories, rtreePolicyType, btreeComparatorFactories,
-                new ConstantMergePolicyProvider(MERGE_THRESHOLD), ThreadCountingOperationTrackerFactory.INSTANCE,
-                SynchronousSchedulerProvider.INSTANCE, NoOpIOOperationCallback.INSTANCE, linearizerCmpFactory,
-                DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE);
+                virtualBufferCacheProvider, new ConstantMergePolicyProvider(MERGE_THRESHOLD),
+                ThreadCountingOperationTrackerFactory.INSTANCE, SynchronousSchedulerProvider.INSTANCE,
+                NoOpIOOperationCallback.INSTANCE, linearizerCmpFactory, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE);
     }
 }
diff --git a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java
index bb31dcd..992198d 100644
--- a/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java
+++ b/hyracks/hyracks-examples/hyracks-integration-tests/src/test/java/edu/uci/ics/hyracks/tests/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesOperatorTestHelper.java
@@ -40,7 +40,7 @@
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             IBinaryComparatorFactory[] btreeComparatorFactories, ILinearizeComparatorFactory linearizerCmpFactory) {
         return new LSMRTreeWithAntiMatterTuplesDataflowHelperFactory(valueProviderFactories, rtreePolicyType,
-                btreeComparatorFactories, new ConstantMergePolicyProvider(MERGE_THRESHOLD),
+                btreeComparatorFactories, virtualBufferCacheProvider, new ConstantMergePolicyProvider(MERGE_THRESHOLD),
                 ThreadCountingOperationTrackerFactory.INSTANCE, SynchronousSchedulerProvider.INSTANCE,
                 NoOpIOOperationCallback.INSTANCE, linearizerCmpFactory);
     }
diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IInMemoryFreePageManager.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IInMemoryFreePageManager.java
deleted file mode 100644
index 67935a7..0000000
--- a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IInMemoryFreePageManager.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.common.api;
-
-public interface IInMemoryFreePageManager extends IFreePageManager {
-    public int getCapacity();
-
-    public void reset();
-
-    public boolean isFull();
-}
diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexLifecycleManager.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexLifecycleManager.java
index c4f43b9..854d34e 100644
--- a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexLifecycleManager.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IIndexLifecycleManager.java
@@ -5,7 +5,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 
 public interface IIndexLifecycleManager {
-    public IIndex getIndex(long resourceID);
+    public IIndex getIndex(long resourceID) throws HyracksDataException;
 
     public void register(long resourceID, IIndex index) throws HyracksDataException;
 
@@ -13,7 +13,7 @@
 
     public void open(long resourceID) throws HyracksDataException;
 
-    public void close(long resourceID);
+    public void close(long resourceID) throws HyracksDataException;
 
     public List<IIndex> getOpenIndexes();
 }
\ No newline at end of file
diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IVirtualFreePageManager.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IVirtualFreePageManager.java
new file mode 100644
index 0000000..e6819b9
--- /dev/null
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/api/IVirtualFreePageManager.java
@@ -0,0 +1,7 @@
+package edu.uci.ics.hyracks.storage.am.common.api;
+
+public interface IVirtualFreePageManager extends IFreePageManager {
+    public int getCapacity();
+
+    public void reset();
+}
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
index eb2e760..bc5fb81 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelper.java
@@ -17,54 +17,43 @@
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
-import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
 
 public class LSMBTreeDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES,
-                DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy, opTrackerFactory, ioScheduler,
-                ioOpCallbackProvider);
+            IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
+                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
     }
 
     public LSMBTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            int memPageSize, int memNumPages, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, bloomFilterFalsePositiveRate, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackProvider);
     }
 
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
         AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
-        ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
-        IInMemoryBufferCache memBufferCache = new InMemoryBufferCache(new HeapBufferAllocator(), memPageSize,
-                memNumPages, new TransientFileMapManager());
-        IInMemoryFreePageManager memFreePageManager = new InMemoryFreePageManager(memNumPages, metaDataFrameFactory);
-        return LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ctx.getIOManager(), file, opDesc
-                .getStorageManager().getBufferCache(ctx), opDesc.getStorageManager().getFileMapProvider(ctx),
-                treeOpDesc.getTreeIndexTypeTraits(), treeOpDesc.getTreeIndexComparatorFactories(), treeOpDesc
-                        .getTreeIndexBloomFilterKeyFields(), bloomFilterFalsePositiveRate, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider,
-                opDesc.getFileSplitProvider().getFileSplits()[partition].getIODeviceId());
+        return LSMBTreeUtils.createLSMTree(virtualBufferCache, ctx.getIOManager(), file, opDesc.getStorageManager()
+                .getBufferCache(ctx), opDesc.getStorageManager().getFileMapProvider(ctx), treeOpDesc
+                .getTreeIndexTypeTraits(), treeOpDesc.getTreeIndexComparatorFactories(), treeOpDesc
+                .getTreeIndexBloomFilterKeyFields(), bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory
+                .createOperationTracker(ctx), ioScheduler, ioOpCallbackProvider, opDesc.getFileSplitProvider()
+                .getFileSplits()[partition].getIODeviceId());
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
index e706786..cc752b9 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/dataflow/LSMBTreeDataflowHelperFactory.java
@@ -21,26 +21,28 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 
 public class LSMBTreeDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
 
     private static final long serialVersionUID = 1L;
 
-    public LSMBTreeDataflowHelperFactory(ILSMMergePolicyProvider mergePolicyProvider,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider, int memPageSize, int memNumPages,
+    public LSMBTreeDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerFactory,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             double bloomFilterFalsePositiveRate) {
-        super(mergePolicyProvider, opTrackerFactory, ioSchedulerProvider, ioOpCallbackProvider, memPageSize,
-                memNumPages, bloomFilterFalsePositiveRate);
+        super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerFactory, ioSchedulerProvider,
+                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        return new LSMBTreeDataflowHelper(opDesc, ctx, partition, memPageSize, memNumPages,
-                bloomFilterFalsePositiveRate, mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory,
-                ioSchedulerProvider.getIOScheduler(ctx), ioOpCallbackProvider);
+        return new LSMBTreeDataflowHelper(opDesc, ctx, partition,
+                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
+                ioOpCallbackProvider);
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
index 1652f5a..8cf2af4 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
@@ -34,7 +34,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
@@ -51,7 +50,6 @@
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeTupleReference;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
@@ -63,8 +61,9 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractLSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallbackWrapper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
@@ -89,20 +88,19 @@
     private final ITreeIndexFrameFactory deleteLeafFrameFactory;
     private final IBinaryComparatorFactory[] cmpFactories;
 
-    public LSMBTree(IInMemoryBufferCache memBufferCache, IInMemoryFreePageManager memFreePageManager,
-            ITreeIndexFrameFactory interiorFrameFactory, ITreeIndexFrameFactory insertLeafFrameFactory,
-            ITreeIndexFrameFactory deleteLeafFrameFactory, ILSMIndexFileManager fileManager,
-            TreeIndexFactory<BTree> diskBTreeFactory, TreeIndexFactory<BTree> bulkLoadBTreeFactory,
-            BloomFilterFactory bloomFilterFactory, double bloomFilterFalsePositiveRate,
-            IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] cmpFactories,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+    public LSMBTree(IVirtualBufferCache virtualBufferCache, ITreeIndexFrameFactory interiorFrameFactory,
+            ITreeIndexFrameFactory insertLeafFrameFactory, ITreeIndexFrameFactory deleteLeafFrameFactory,
+            ILSMIndexFileManager fileManager, TreeIndexFactory<BTree> diskBTreeFactory,
+            TreeIndexFactory<BTree> bulkLoadBTreeFactory, BloomFilterFactory bloomFilterFactory,
+            double bloomFilterFalsePositiveRate, IFileMapProvider diskFileMapProvider, int fieldCount,
+            IBinaryComparatorFactory[] cmpFactories, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(memFreePageManager, diskBTreeFactory.getBufferCache(), fileManager, diskFileMapProvider,
-                bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
-        mutableComponent = new LSMBTreeMutableComponent(new BTree(memBufferCache,
-                ((InMemoryBufferCache) memBufferCache).getFileMapProvider(), memFreePageManager, interiorFrameFactory,
-                insertLeafFrameFactory, cmpFactories, fieldCount, new FileReference(new File("membtree"))),
-                memFreePageManager);
+        super(virtualBufferCache, diskBTreeFactory.getBufferCache(), fileManager, diskFileMapProvider,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
+        mutableComponent = new LSMBTreeMutableComponent(new BTree(virtualBufferCache,
+                virtualBufferCache.getFileMapProvider(), new VirtualFreePageManager(virtualBufferCache.getNumPages()),
+                interiorFrameFactory, insertLeafFrameFactory, cmpFactories, fieldCount, new FileReference(new File(
+                        fileManager.getBaseDir() + "_virtual"))), virtualBufferCache);
         this.insertLeafFrameFactory = insertLeafFrameFactory;
         this.deleteLeafFrameFactory = deleteLeafFrameFactory;
         this.cmpFactories = cmpFactories;
@@ -127,7 +125,7 @@
             return;
         }
 
-        ((InMemoryBufferCache) mutableComponent.getBTree().getBufferCache()).open();
+        ((IVirtualBufferCache) mutableComponent.getBTree().getBufferCache()).open();
         mutableComponent.getBTree().create();
         mutableComponent.getBTree().activate();
         List<ILSMComponent> immutableComponents = componentsRef.get();
@@ -180,7 +178,7 @@
         }
         mutableComponent.getBTree().deactivate();
         mutableComponent.getBTree().destroy();
-        ((InMemoryBufferCache) mutableComponent.getBTree().getBufferCache()).close();
+        ((IVirtualBufferCache) mutableComponent.getBTree().getBufferCache()).close();
         isActivated = false;
     }
 
@@ -622,8 +620,8 @@
 
     @Override
     public long getMemoryAllocationSize() {
-        InMemoryBufferCache memBufferCache = (InMemoryBufferCache) mutableComponent.getBTree().getBufferCache();
-        return memBufferCache.getNumPages() * memBufferCache.getPageSize();
+        IBufferCache virtualBufferCache = mutableComponent.getBTree().getBufferCache();
+        return virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMutableComponent.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMutableComponent.java
index d340599..5444d6b 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreeMutableComponent.java
@@ -17,17 +17,17 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMutableLSMComponent;
 
 public class LSMBTreeMutableComponent extends AbstractMutableLSMComponent {
 
     private final BTree btree;
-    private final IInMemoryFreePageManager mfpm;
+    private final IVirtualBufferCache vbc;
 
-    public LSMBTreeMutableComponent(BTree btree, IInMemoryFreePageManager mfpm) {
+    public LSMBTreeMutableComponent(BTree btree, IVirtualBufferCache vbc) {
         this.btree = btree;
-        this.mfpm = mfpm;
+        this.vbc = vbc;
     }
 
     public BTree getBTree() {
@@ -36,13 +36,16 @@
 
     @Override
     protected boolean isFull() {
-        return mfpm.isFull();
+        return vbc.isFull();
     }
 
     @Override
     protected void reset() throws HyracksDataException {
         super.reset();
-        btree.clear();
+        btree.deactivate();
+        btree.destroy();
+        btree.create();
+        btree.activate();
     }
 
 }
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java
index 5736200..c61a63c 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTreePointSearchCursor.java
@@ -122,6 +122,7 @@
 
     @Override
     public void reset() throws HyracksDataException, IndexException {
+        try {
         if (rangeCursors != null) {
             for (int i = 0; i < rangeCursors.length; ++i) {
                 rangeCursors[i].reset();
@@ -130,6 +131,11 @@
         rangeCursors = null;
         nextHasBeenCalled = false;
         foundTuple = false;
+        } finally {
+            if (lsmHarness != null) {
+                lsmHarness.endSearch(opCtx);
+            }
+        }
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
index d92e93d..7707712 100644
--- a/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
+++ b/hyracks/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeUtils.java
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeNSMLeafFrameFactory;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManagerFactory;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
@@ -33,23 +32,33 @@
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTreeFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeCopyTupleWriterFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.tuples.LSMBTreeTupleWriterFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public class LSMBTreeUtils {
-    public static LSMBTree createLSMTree(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
-            IBinaryComparatorFactory[] cmpFactories, int[] bloomFilterKeyFields, double bloomFilterFalsePositiveRate,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+
+    public static LSMBTree createLSMTree(IVirtualBufferCache virtualBufferCache, IIOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories, int[] bloomFilterKeyFields,
+            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        return createLSMTree(virtualBufferCache, ioManager, file, diskBufferCache, diskFileMapProvider, typeTraits,
+                cmpFactories, bloomFilterKeyFields, bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler,
+                ioOpCallbackProvider, 0);
+    }
+
+    public static LSMBTree createLSMTree(IVirtualBufferCache virtualBufferCache, IIOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories, int[] bloomFilterKeyFields,
+            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider, int ioDeviceId) {
         LSMBTreeTupleWriterFactory insertTupleWriterFactory = new LSMBTreeTupleWriterFactory(typeTraits,
                 cmpFactories.length, false);
@@ -77,10 +86,10 @@
         ILSMIndexFileManager fileNameManager = new LSMBTreeFileManager(ioManager, diskFileMapProvider, file,
                 diskBTreeFactory, ioDeviceId);
 
-        LSMBTree lsmTree = new LSMBTree(memBufferCache, memFreePageManager, interiorFrameFactory,
-                insertLeafFrameFactory, deleteLeafFrameFactory, fileNameManager, diskBTreeFactory,
-                bulkLoadBTreeFactory, bloomFilterFactory, bloomFilterFalsePositiveRate, diskFileMapProvider,
-                typeTraits.length, cmpFactories, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        LSMBTree lsmTree = new LSMBTree(virtualBufferCache, interiorFrameFactory, insertLeafFrameFactory,
+                deleteLeafFrameFactory, fileNameManager, diskBTreeFactory, bulkLoadBTreeFactory, bloomFilterFactory,
+                bloomFilterFalsePositiveRate, diskFileMapProvider, typeTraits.length, cmpFactories, mergePolicy,
+                opTracker, ioScheduler, ioOpCallbackProvider);
         return lsmTree;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IInMemoryBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IInMemoryBufferCache.java
deleted file mode 100644
index 082ad2f..0000000
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IInMemoryBufferCache.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.api;
-
-import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCacheInternal;
-
-public interface IInMemoryBufferCache extends IBufferCacheInternal {
-    public void open();
-}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
index f2c052b..bec8a2e 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMIndexInternal.java
@@ -19,7 +19,6 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
@@ -59,12 +58,12 @@
      */
     public void getOperationalComponents(ILSMIndexOperationContext ctx);
 
-    public IInMemoryFreePageManager getInMemoryFreePageManager();
-
     public List<ILSMComponent> getImmutableComponents();
 
     public void markAsValid(ILSMComponent lsmComponent) throws HyracksDataException;
 
     public void setFlushStatus(boolean needsFlush);
 
+    public boolean isFull();
+
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
index c3f1f3e..273f589 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTracker.java
@@ -22,7 +22,7 @@
      * then this method does not block and returns false.
      * Otherwise, this method returns true, and the operation is considered 'active' in the index.
      */
-    public void beforeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+    public void beforeOperation(ILSMIndex index, LSMOperationType opType, ISearchOperationCallback searchCallback,
             IModificationOperationCallback modificationCallback) throws HyracksDataException;
 
     /**
@@ -31,7 +31,7 @@
      * After this method has been called, the operation is still considered 'active',
      * until the issuer of the operation declares it completed by calling completeOperation().
      */
-    public void afterOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+    public void afterOperation(ILSMIndex index, LSMOperationType opType, ISearchOperationCallback searchCallback,
             IModificationOperationCallback modificationCallback) throws HyracksDataException;
 
     /**
@@ -39,6 +39,6 @@
      * The use of this method indicates that the operation is no longer 'active'
      * for the purpose of coordinating flushes/merges.
      */
-    public void completeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+    public void completeOperation(ILSMIndex index, LSMOperationType opType, ISearchOperationCallback searchCallback,
             IModificationOperationCallback modificationCallback) throws HyracksDataException;
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java
deleted file mode 100644
index db7ff6c..0000000
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerFactory.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package edu.uci.ics.hyracks.storage.am.lsm.common.api;
-
-import java.io.Serializable;
-
-public interface ILSMOperationTrackerFactory extends Serializable {
-    public ILSMOperationTracker createOperationTracker(ILSMIndex index);
-}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerProvider.java
new file mode 100644
index 0000000..0607624
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/ILSMOperationTrackerProvider.java
@@ -0,0 +1,9 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+
+public interface ILSMOperationTrackerProvider extends Serializable {
+    public ILSMOperationTracker createOperationTracker(IHyracksTaskContext ctx);
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCache.java
new file mode 100644
index 0000000..35d6162
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCache.java
@@ -0,0 +1,14 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapManager;
+
+public interface IVirtualBufferCache extends IBufferCache {
+    public void open();
+
+    public boolean isFull();
+
+    public void reset();
+
+    public IFileMapManager getFileMapProvider();
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCacheProvider.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCacheProvider.java
new file mode 100644
index 0000000..06f8bd9
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/api/IVirtualBufferCacheProvider.java
@@ -0,0 +1,9 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.api;
+
+import java.io.Serializable;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+
+public interface IVirtualBufferCacheProvider extends Serializable {
+    public IVirtualBufferCache getVirtualBufferCache(IHyracksTaskContext ctx);
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
index 6202518..d7e5a22 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelper.java
@@ -21,38 +21,35 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 
 public abstract class AbstractLSMIndexDataflowHelper extends IndexDataflowHelper {
 
-    protected static int DEFAULT_MEM_PAGE_SIZE = 32768;
-    protected static int DEFAULT_MEM_NUM_PAGES = 1000;
     protected static double DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE = 0.01;
 
-    protected final int memPageSize;
-    protected final int memNumPages;
     protected final double bloomFilterFalsePositiveRate;
 
+    protected final IVirtualBufferCache virtualBufferCache;
     protected final ILSMMergePolicy mergePolicy;
     protected final ILSMIOOperationScheduler ioScheduler;
-    protected final ILSMOperationTrackerFactory opTrackerFactory;
+    protected final ILSMOperationTrackerProvider opTrackerFactory;
     protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
 
     public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES,
-                DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy, opTrackerFactory, ioScheduler,
-                ioOpCallbackProvider);
+            IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
+                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
     }
 
     public AbstractLSMIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            int memPageSize, int memNumPages, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
         super(opDesc, ctx, partition);
-        this.memPageSize = memPageSize;
-        this.memNumPages = memNumPages;
+        this.virtualBufferCache = virtualBufferCache;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.mergePolicy = mergePolicy;
         this.opTrackerFactory = opTrackerFactory;
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
index bc4271c..1ff1251 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/AbstractLSMIndexDataflowHelperFactory.java
@@ -19,29 +19,28 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
 
 public abstract class AbstractLSMIndexDataflowHelperFactory implements IIndexDataflowHelperFactory {
     protected static final long serialVersionUID = 1L;
 
+    protected final IVirtualBufferCacheProvider virtualBufferCacheProvider;
     protected final ILSMMergePolicyProvider mergePolicyProvider;
-    protected final ILSMOperationTrackerFactory opTrackerFactory;
+    protected final ILSMOperationTrackerProvider opTrackerFactory;
     protected final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
     protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
-    protected final int memPageSize;
-    protected final int memNumPages;
     protected final double bloomFilterFalsePositiveRate;
 
-    public AbstractLSMIndexDataflowHelperFactory(ILSMMergePolicyProvider mergePolicyProvider,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider, int memPageSize, int memNumPages,
+    public AbstractLSMIndexDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerFactory,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             double bloomFilterFalsePositiveRate) {
+        this.virtualBufferCacheProvider = virtualBufferCacheProvider;
         this.mergePolicyProvider = mergePolicyProvider;
         this.opTrackerFactory = opTrackerFactory;
         this.ioSchedulerProvider = ioSchedulerProvider;
         this.ioOpCallbackProvider = ioOpCallbackProvider;
-        this.memPageSize = memPageSize;
-        this.memNumPages = memNumPages;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
index a3e84ed..fdfcbd4 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMIndexInsertUpdateDeleteOperatorNodePushable.java
@@ -39,7 +39,7 @@
     public void nextFrame(ByteBuffer buffer) throws HyracksDataException {
         accessor.reset(buffer);
         ILSMIndexAccessor lsmAccessor = (ILSMIndexAccessor) indexAccessor;
-        int lastFlushedTupleIndex = 0;
+        int nextFlushTupleIndex = 0;
         int tupleCount = accessor.getTupleCount();
         for (int i = 0; i < tupleCount; i++) {
             try {
@@ -55,32 +55,32 @@
                 switch (op) {
                     case INSERT: {
                         if (!lsmAccessor.tryInsert(tuple)) {
-                            flushPartialFrame(lastFlushedTupleIndex, i);
-                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            flushPartialFrame(nextFlushTupleIndex, i);
+                            nextFlushTupleIndex = i;
                             lsmAccessor.insert(tuple);
                         }
                         break;
                     }
                     case DELETE: {
                         if (!lsmAccessor.tryDelete(tuple)) {
-                            flushPartialFrame(lastFlushedTupleIndex, i);
-                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            flushPartialFrame(nextFlushTupleIndex, i);
+                            nextFlushTupleIndex = i;
                             lsmAccessor.delete(tuple);
                         }
                         break;
                     }
                     case UPSERT: {
                         if (!lsmAccessor.tryUpsert(tuple)) {
-                            flushPartialFrame(lastFlushedTupleIndex, i);
-                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            flushPartialFrame(nextFlushTupleIndex, i);
+                            nextFlushTupleIndex = i;
                             lsmAccessor.upsert(tuple);
                         }
                         break;
                     }
                     case UPDATE: {
                         if (!lsmAccessor.tryUpdate(tuple)) {
-                            flushPartialFrame(lastFlushedTupleIndex, i);
-                            lastFlushedTupleIndex = (i == 0) ? 0 : i - 1;
+                            flushPartialFrame(nextFlushTupleIndex, i);
+                            nextFlushTupleIndex = i;
                             lsmAccessor.update(tuple);
                         }
                         break;
@@ -96,13 +96,13 @@
                 throw new HyracksDataException(e);
             }
         }
-        if (lastFlushedTupleIndex == 0) {
+        if (nextFlushTupleIndex == 0) {
             // No partial flushing was necessary. Forward entire frame.
             System.arraycopy(buffer.array(), 0, writeBuffer.array(), 0, buffer.capacity());
             FrameUtils.flushFrame(writeBuffer, writer);
         } else {
             // Flush remaining partial frame.
-            flushPartialFrame(lastFlushedTupleIndex, tupleCount);
+            flushPartialFrame(nextFlushTupleIndex, tupleCount);
         }
     }
 
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexInsertUpdateDeleteOperatorDescriptor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexInsertUpdateDeleteOperatorDescriptor.java
index 6297576..0dbb6a7 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexInsertUpdateDeleteOperatorDescriptor.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/dataflow/LSMTreeIndexInsertUpdateDeleteOperatorDescriptor.java
@@ -37,8 +37,8 @@
 
     private static final long serialVersionUID = 1L;
 
-    private final int[] fieldPermutation;
-    private final IndexOperation op;
+    protected final int[] fieldPermutation;
+    protected final IndexOperation op;
 
     public LSMTreeIndexInsertUpdateDeleteOperatorDescriptor(IOperatorDescriptorRegistry spec, RecordDescriptor recDesc,
             IStorageManagerInterface storageManager, IIndexLifecycleManagerProvider lifecycleManagerProvider,
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryBufferCache.java
deleted file mode 100644
index c24c473..0000000
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryBufferCache.java
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package edu.uci.ics.hyracks.storage.am.lsm.common.freepage;
-
-import java.nio.ByteBuffer;
-
-import edu.uci.ics.hyracks.storage.common.buffercache.ICacheMemoryAllocator;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
-import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
-import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
-
-/**
- * In-memory buffer cache that supports two tree indexes.
- * We assume that the tree indexes have 2 fixed pages, one at index 0 (metadata page), and one at index 1 (root page).
- */
-public class DualIndexInMemoryBufferCache extends InMemoryBufferCache {
-
-    public DualIndexInMemoryBufferCache(ICacheMemoryAllocator allocator, int pageSize, int numPages) {
-        super(allocator, pageSize, numPages, new TransientFileMapManager());
-    }
-
-    @Override
-    public ICachedPage pin(long dpid, boolean newPage) {
-        int pageId = BufferedFileHandle.getPageId(dpid);
-        int fileId = BufferedFileHandle.getFileId(dpid);
-        if (pageId < pages.length) {
-            // Common case: Return regular page.
-            if (pageId == 0 || pageId == 1) {
-                return pages[pageId + 2 * fileId];
-            } else {
-                return pages[pageId];
-            }
-        } else {
-            // Rare case: Return overflow page, possibly expanding overflow
-            // array.
-            synchronized (overflowPages) {
-                int numNewPages = pageId - pages.length - overflowPages.size() + 1;
-                if (numNewPages > 0) {
-                    ByteBuffer[] buffers = allocator.allocate(pageSize, numNewPages);
-                    for (int i = 0; i < numNewPages; i++) {
-                        CachedPage overflowPage = new CachedPage(pages.length + overflowPages.size(), buffers[i]);
-                        overflowPages.add(overflowPage);
-                    }
-                }
-                return overflowPages.get(pageId - pages.length);
-            }
-        }
-    }
-
-}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryFreePageManager.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryFreePageManager.java
deleted file mode 100644
index 7a2be7f..0000000
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/DualIndexInMemoryFreePageManager.java
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package edu.uci.ics.hyracks.storage.am.lsm.common.freepage;
-
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
-
-/**
- * In-memory free page manager that supports two tree indexes.
- * We assume that the tree indexes have 2 fixed pages, one at index 0 (metadata page), and one at index 1 (root page).
- */
-public class DualIndexInMemoryFreePageManager extends InMemoryFreePageManager {
-
-    public DualIndexInMemoryFreePageManager(int capacity, ITreeIndexMetaDataFrameFactory metaDataFrameFactory) {
-        super(capacity, metaDataFrameFactory);
-        // We start the currentPageId from 3, because the RTree uses
-        // the first page as metadata page, and the second page as root page.
-        // And the BTree uses the third page as metadata, and the third page as root page 
-        // (when returning free pages we first increment, then get)
-        currentPageId.set(3);
-    }
-
-    @Override
-    public void init(ITreeIndexMetaDataFrame metaFrame, int currentMaxPage) throws HyracksDataException {
-        currentPageId.set(3);
-    }
-
-    public int getCapacity() {
-        return capacity - 4;
-    }
-
-    public void reset() {
-        currentPageId.set(3);
-    }
-}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryBufferCache.java
deleted file mode 100644
index 66d8ec2..0000000
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryBufferCache.java
+++ /dev/null
@@ -1,206 +0,0 @@
-/*
- * Copyright 2009-2012 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package edu.uci.ics.hyracks.storage.am.lsm.common.freepage;
-
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.locks.ReadWriteLock;
-import java.util.concurrent.locks.ReentrantReadWriteLock;
-
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.api.io.FileReference;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICacheMemoryAllocator;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPageInternal;
-import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
-import edu.uci.ics.hyracks.storage.common.file.IFileMapManager;
-import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
-
-public class InMemoryBufferCache implements IInMemoryBufferCache {
-    protected final ICacheMemoryAllocator allocator;
-    protected final IFileMapManager fileMapManager;
-    protected final int pageSize;
-    protected final int numPages;
-    protected final List<CachedPage> overflowPages = new ArrayList<CachedPage>();
-    protected CachedPage[] pages;
-
-    public InMemoryBufferCache(ICacheMemoryAllocator allocator, int pageSize, int numPages,
-            IFileMapManager fileMapManager) {
-        this.allocator = allocator;
-        this.fileMapManager = fileMapManager;
-        this.pageSize = pageSize;
-        this.numPages = numPages;
-    }
-
-    public void open() {
-        pages = new CachedPage[numPages];
-        ByteBuffer[] buffers = allocator.allocate(pageSize, numPages);
-        for (int i = 0; i < buffers.length; ++i) {
-            pages[i] = new CachedPage(i, buffers[i]);
-        }
-    }
-
-    @Override
-    public ICachedPage pin(long dpid, boolean newPage) {
-        int pageId = BufferedFileHandle.getPageId(dpid);
-        if (pageId < pages.length) {
-            // Common case: Return regular page.
-            return pages[pageId];
-        } else {
-            // Rare case: Return overflow page, possibly expanding overflow array.
-            synchronized (overflowPages) {
-                int numNewPages = pageId - pages.length - overflowPages.size() + 1;
-                if (numNewPages > 0) {
-                    ByteBuffer[] buffers = allocator.allocate(pageSize, numNewPages);
-                    for (int i = 0; i < numNewPages; i++) {
-                        CachedPage overflowPage = new CachedPage(pages.length + overflowPages.size(), buffers[i]);
-                        overflowPages.add(overflowPage);
-                    }
-                }
-                return overflowPages.get(pageId - pages.length);
-            }
-        }
-    }
-
-    @Override
-    public ICachedPage tryPin(long dpid) throws HyracksDataException {
-        return pin(dpid, false);
-    }
-
-    @Override
-    public int getPageSize() {
-        return pageSize;
-    }
-
-    @Override
-    public int getNumPages() {
-        return numPages;
-    }
-
-    @Override
-    public ICachedPageInternal getPage(int cpid) {
-        return pages[cpid];
-    }
-
-    public int getNumOverflowPages() {
-        return overflowPages.size();
-    }
-
-    @Override
-    public void createFile(FileReference fileRef) throws HyracksDataException {
-        synchronized (fileMapManager) {
-            fileMapManager.registerFile(fileRef);
-        }
-    }
-
-    @Override
-    public void openFile(int fileId) throws HyracksDataException {
-        // Do nothing.
-    }
-
-    @Override
-    public void closeFile(int fileId) throws HyracksDataException {
-        // Do nothing.
-    }
-
-    @Override
-    public void deleteFile(int fileId, boolean flushDirtyPages) throws HyracksDataException {
-        synchronized (fileMapManager) {
-            fileMapManager.unregisterFile(fileId);
-        }
-    }
-
-    @Override
-    public void unpin(ICachedPage page) throws HyracksDataException {
-        // Do Nothing.
-    }
-
-    @Override
-    public void close() {
-        for (int i = 0; i < numPages; ++i) {
-            pages[i] = null;
-        }
-        overflowPages.clear();
-    }
-
-    public class CachedPage implements ICachedPageInternal {
-        private final int cpid;
-        private final ByteBuffer buffer;
-        private final ReadWriteLock latch;
-
-        public CachedPage(int cpid, ByteBuffer buffer) {
-            this.cpid = cpid;
-            this.buffer = buffer;
-            latch = new ReentrantReadWriteLock(true);
-        }
-
-        @Override
-        public ByteBuffer getBuffer() {
-            return buffer;
-        }
-
-        @Override
-        public Object getReplacementStrategyObject() {
-            // Do nothing.
-            return null;
-        }
-
-        @Override
-        public boolean pinIfGoodVictim() {
-            // Do nothing.
-            return false;
-        }
-
-        @Override
-        public int getCachedPageId() {
-            return cpid;
-        }
-
-        @Override
-        public void acquireReadLatch() {
-            latch.readLock().lock();
-        }
-
-        @Override
-        public void acquireWriteLatch() {
-            latch.writeLock().lock();
-        }
-
-        @Override
-        public void releaseReadLatch() {
-            latch.readLock().unlock();
-        }
-
-        @Override
-        public void releaseWriteLatch() {
-            latch.writeLock().unlock();
-        }
-    }
-
-    @Override
-    public void force(int fileId, boolean metadata) throws HyracksDataException {
-    }
-
-    @Override
-    public void flushDirtyPage(ICachedPage page) throws HyracksDataException {
-    }
-
-    public IFileMapProvider getFileMapProvider() {
-        return fileMapManager;
-    }
-}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryFreePageManager.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/VirtualFreePageManager.java
similarity index 84%
rename from hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryFreePageManager.java
rename to hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/VirtualFreePageManager.java
index c601a9b..823656d 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/InMemoryFreePageManager.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/freepage/VirtualFreePageManager.java
@@ -18,22 +18,20 @@
 import java.util.concurrent.atomic.AtomicInteger;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 
-public class InMemoryFreePageManager implements IInMemoryFreePageManager {
+public class VirtualFreePageManager implements IVirtualFreePageManager {
     protected final int capacity;
     protected final AtomicInteger currentPageId = new AtomicInteger();
-    protected final ITreeIndexMetaDataFrameFactory metaDataFrameFactory;
 
-    public InMemoryFreePageManager(int capacity, ITreeIndexMetaDataFrameFactory metaDataFrameFactory) {
+    public VirtualFreePageManager(int capacity) {
         // We start the currentPageId from 1, because the BTree uses
         // the first page as metadata page, and the second page as root page.
         // (when returning free pages we first increment, then get)
         currentPageId.set(1);
         this.capacity = capacity;
-        this.metaDataFrameFactory = metaDataFrameFactory;
     }
 
     @Override
@@ -55,7 +53,7 @@
 
     @Override
     public ITreeIndexMetaDataFrameFactory getMetaDataFrameFactory() {
-        return metaDataFrameFactory;
+        return NullMetadataFrameFactory.INSTANCE;
     }
 
     public int getCapacity() {
@@ -66,10 +64,6 @@
         currentPageId.set(1);
     }
 
-    public boolean isFull() {
-        return currentPageId.get() >= capacity;
-    }
-
     @Override
     public void addFreePage(ITreeIndexMetaDataFrame metaFrame, int freePage) throws HyracksDataException {
     }
@@ -109,4 +103,14 @@
     public void close() {
         // Method doesn't make sense for this free page manager.
     }
+
+    private static class NullMetadataFrameFactory implements ITreeIndexMetaDataFrameFactory {
+        private static final NullMetadataFrameFactory INSTANCE = new NullMetadataFrameFactory();
+
+        @Override
+        public ITreeIndexMetaDataFrame createFrame() {
+            return null;
+        }
+
+    }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java
index b6fc2f7..053a8a4 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractImmutableLSMComponent.java
@@ -26,6 +26,7 @@
         }
 
         switch (opType) {
+            case FORCE_MODIFICATION:
             case MODIFICATION:
             case SEARCH:
                 readerCount++;
@@ -50,6 +51,7 @@
                 if (failedOperation) {
                     state = ComponentState.READABLE;
                 }
+            case FORCE_MODIFICATION:
             case MODIFICATION:
             case SEARCH:
                 readerCount--;
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
index 6782fbe..f081c37 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
@@ -21,7 +21,6 @@
 import java.util.concurrent.atomic.AtomicReference;
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrame;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
@@ -32,7 +31,7 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexInternal;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
 import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
@@ -45,7 +44,7 @@
     protected final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
 
     // In-memory components.   
-    protected final IInMemoryFreePageManager memFreePageManager;
+    protected final IVirtualBufferCache virtualBufferCache;
 
     // On-disk components.    
     protected final IBufferCache diskBufferCache;
@@ -58,19 +57,17 @@
 
     private boolean needsFlush = false;
 
-    public AbstractLSMIndex(IInMemoryFreePageManager memFreePageManager, IBufferCache diskBufferCache,
+    public AbstractLSMIndex(IVirtualBufferCache virtualBufferCache, IBufferCache diskBufferCache,
             ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider,
-            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this.memFreePageManager = memFreePageManager;
+            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        this.virtualBufferCache = virtualBufferCache;
         this.diskBufferCache = diskBufferCache;
         this.diskFileMapProvider = diskFileMapProvider;
         this.fileManager = fileManager;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.ioScheduler = ioScheduler;
         this.ioOpCallbackProvider = ioOpCallbackProvider;
-        ILSMOperationTracker opTracker = opTrackerFactory.createOperationTracker(this);
         lsmHarness = new LSMHarness(this, mergePolicy, opTracker);
         isActivated = false;
         componentsRef = new AtomicReference<List<ILSMComponent>>();
@@ -158,11 +155,6 @@
     }
 
     @Override
-    public IInMemoryFreePageManager getInMemoryFreePageManager() {
-        return memFreePageManager;
-    }
-
-    @Override
     public List<ILSMComponent> getImmutableComponents() {
         return componentsRef.get();
     }
@@ -188,6 +180,11 @@
     }
 
     @Override
+    public boolean isFull() {
+        return virtualBufferCache.isFull();
+    }
+
+    @Override
     public IBufferCache getBufferCache() {
         return diskBufferCache;
     }
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java
index 5cde7bc..f881378 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/AbstractMutableLSMComponent.java
@@ -8,7 +8,7 @@
     private int readerCount;
     private int writerCount;
     private ComponentState state;
-    
+
     private boolean isModified;
 
     private enum ComponentState {
@@ -100,7 +100,6 @@
         }
         notifyAll();
     }
-    
 
     public void setIsModified() {
         isModified = true;
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
index 7372b86..e1db6e7 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMHarness.java
@@ -49,10 +49,10 @@
     }
 
     private void threadExit(ILSMIndexOperationContext opCtx, LSMOperationType opType) throws HyracksDataException {
-        if (!lsmIndex.getFlushStatus() && lsmIndex.getInMemoryFreePageManager().isFull()) {
+        if (!lsmIndex.getFlushStatus() && lsmIndex.isFull()) {
             lsmIndex.setFlushStatus(true);
         }
-        opTracker.afterOperation(opType, opCtx.getSearchOperationCallback(), opCtx.getModificationCallback());
+        opTracker.afterOperation(lsmIndex, opType, opCtx.getSearchOperationCallback(), opCtx.getModificationCallback());
     }
 
     private boolean getAndEnterComponents(ILSMIndexOperationContext ctx, LSMOperationType opType, boolean tryOperation)
@@ -93,7 +93,7 @@
             }
         }
 
-        opTracker.beforeOperation(opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
+        opTracker.beforeOperation(lsmIndex, opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
         return true;
     }
 
@@ -162,7 +162,7 @@
     @Override
     public void noOp(ILSMIndexOperationContext ctx) throws HyracksDataException {
         LSMOperationType opType = LSMOperationType.NOOP;
-        opTracker.beforeOperation(opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
+        opTracker.beforeOperation(lsmIndex, opType, ctx.getSearchOperationCallback(), ctx.getModificationCallback());
         threadExit(ctx, opType);
     }
 
@@ -191,7 +191,7 @@
             LOGGER.info(lsmIndex + ": flushing");
         }
         ILSMComponent newComponent = lsmIndex.flush(operation);
-        
+
         operation.getCallback().afterOperation(null, newComponent);
         lsmIndex.markAsValid(newComponent);
         operation.getCallback().afterFinalize(newComponent);
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
index 7f08ba4..1eff689 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/LSMIndexSearchCursor.java
@@ -68,16 +68,22 @@
         outputElement = null;
         needPush = false;
 
-        if (outputPriorityQueue != null) {
-            outputPriorityQueue.clear();
-        }
+        try {
+            if (outputPriorityQueue != null) {
+                outputPriorityQueue.clear();
+            }
 
-        if (rangeCursors != null) {
-            for (int i = 0; i < rangeCursors.length; i++) {
-                rangeCursors[i].reset();
+            if (rangeCursors != null) {
+                for (int i = 0; i < rangeCursors.length; i++) {
+                    rangeCursors[i].reset();
+                }
+            }
+            rangeCursors = null;
+        } finally {
+            if (lsmHarness != null) {
+                lsmHarness.endSearch(opCtx);
             }
         }
-        rangeCursors = null;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/MultitenantVirtualBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/MultitenantVirtualBufferCache.java
new file mode 100644
index 0000000..1ad7f5d
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/MultitenantVirtualBufferCache.java
@@ -0,0 +1,102 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapManager;
+
+public class MultitenantVirtualBufferCache implements IVirtualBufferCache {
+
+    private final IVirtualBufferCache vbc;
+    private int openCount;
+
+    public MultitenantVirtualBufferCache(IVirtualBufferCache virtualBufferCache) {
+        this.vbc = virtualBufferCache;
+        openCount = 0;
+    }
+
+    @Override
+    public void createFile(FileReference fileRef) throws HyracksDataException {
+        vbc.createFile(fileRef);
+    }
+
+    @Override
+    public void openFile(int fileId) throws HyracksDataException {
+        vbc.openFile(fileId);
+    }
+
+    @Override
+    public void closeFile(int fileId) throws HyracksDataException {
+        vbc.closeFile(fileId);
+    }
+
+    @Override
+    public void deleteFile(int fileId, boolean flushDirtyPages) throws HyracksDataException {
+        vbc.deleteFile(fileId, flushDirtyPages);
+    }
+
+    @Override
+    public ICachedPage tryPin(long dpid) throws HyracksDataException {
+        return vbc.tryPin(dpid);
+    }
+
+    @Override
+    public ICachedPage pin(long dpid, boolean newPage) throws HyracksDataException {
+        return vbc.pin(dpid, newPage);
+    }
+
+    @Override
+    public void unpin(ICachedPage page) throws HyracksDataException {
+        vbc.unpin(page);
+    }
+
+    @Override
+    public void flushDirtyPage(ICachedPage page) throws HyracksDataException {
+        vbc.flushDirtyPage(page);
+    }
+
+    @Override
+    public void force(int fileId, boolean metadata) throws HyracksDataException {
+        vbc.force(fileId, metadata);
+    }
+
+    @Override
+    public int getPageSize() {
+        return vbc.getPageSize();
+    }
+
+    @Override
+    public int getNumPages() {
+        return vbc.getNumPages();
+    }
+
+    @Override
+    public synchronized void close() {
+        --openCount;
+        if (openCount == 0) {
+            vbc.close();
+        }
+    }
+
+    @Override
+    public synchronized void open() {
+        ++openCount;
+        vbc.open();
+    }
+
+    @Override
+    public boolean isFull() {
+        return vbc.isFull();
+    }
+
+    @Override
+    public void reset() {
+        vbc.reset();
+    }
+
+    @Override
+    public IFileMapManager getFileMapProvider() {
+        return vbc.getFileMapProvider();
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpOperationTrackerFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpOperationTrackerFactory.java
index 97ec50e..6a0d652 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpOperationTrackerFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/NoOpOperationTrackerFactory.java
@@ -1,11 +1,12 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
 
 /**
  * Operation tracker that does nothing.
@@ -13,29 +14,32 @@
  * It is assumed than an op tracker cooperates with an lsm index to synchronize flushes with
  * regular operations, and this implementation does no such tracking at all.
  */
-public class NoOpOperationTrackerFactory implements ILSMOperationTrackerFactory {
+public class NoOpOperationTrackerFactory implements ILSMOperationTrackerProvider {
     private static final long serialVersionUID = 1L;
 
     public static NoOpOperationTrackerFactory INSTANCE = new NoOpOperationTrackerFactory();
 
     @Override
-    public ILSMOperationTracker createOperationTracker(ILSMIndex index) {
+    public ILSMOperationTracker createOperationTracker(IHyracksTaskContext ctx) {
         return new ILSMOperationTracker() {
 
             @Override
-            public void completeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
-                    IModificationOperationCallback modificationCallback) throws HyracksDataException {
+            public void completeOperation(ILSMIndex index, LSMOperationType opType,
+                    ISearchOperationCallback searchCallback, IModificationOperationCallback modificationCallback)
+                    throws HyracksDataException {
                 // Do nothing.
             }
 
             @Override
-            public void beforeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
-                    IModificationOperationCallback modificationCallback) throws HyracksDataException {
+            public void beforeOperation(ILSMIndex index, LSMOperationType opType,
+                    ISearchOperationCallback searchCallback, IModificationOperationCallback modificationCallback)
+                    throws HyracksDataException {
             }
 
             @Override
-            public void afterOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
-                    IModificationOperationCallback modificationCallback) throws HyracksDataException {
+            public void afterOperation(ILSMIndex index, LSMOperationType opType,
+                    ISearchOperationCallback searchCallback, IModificationOperationCallback modificationCallback)
+                    throws HyracksDataException {
                 // Do nothing.                        
             }
         };
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingOperationTrackerFactory.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingOperationTrackerFactory.java
index 3b4b00f..13bcd9a 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingOperationTrackerFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingOperationTrackerFactory.java
@@ -1,18 +1,18 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
 
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
 
-public class ThreadCountingOperationTrackerFactory implements ILSMOperationTrackerFactory {
+public class ThreadCountingOperationTrackerFactory implements ILSMOperationTrackerProvider {
 
     private static final long serialVersionUID = 1L;
-    
-    public static ThreadCountingOperationTrackerFactory INSTANCE = new ThreadCountingOperationTrackerFactory(); 
-    
+
+    public static ThreadCountingOperationTrackerFactory INSTANCE = new ThreadCountingOperationTrackerFactory();
+
     @Override
-    public ILSMOperationTracker createOperationTracker(ILSMIndex index) {
-        return new ThreadCountingTracker(index);
+    public ILSMOperationTracker createOperationTracker(IHyracksTaskContext ctx) {
+        return new ThreadCountingTracker();
     }
 
     // Enforce singleton.
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
index 5dfa94e..a84ddd1 100644
--- a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/ThreadCountingTracker.java
@@ -12,15 +12,13 @@
 
 public class ThreadCountingTracker implements ILSMOperationTracker {
     private final AtomicInteger threadRefCount;
-    private final ILSMIndex index;
 
-    public ThreadCountingTracker(ILSMIndex index) {
-        this.index = index;
+    public ThreadCountingTracker() {
         this.threadRefCount = new AtomicInteger();
     }
 
     @Override
-    public void beforeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+    public void beforeOperation(ILSMIndex index, LSMOperationType opType, ISearchOperationCallback searchCallback,
             IModificationOperationCallback modificationCallback) throws HyracksDataException {
         if (opType == LSMOperationType.MODIFICATION) {
             threadRefCount.incrementAndGet();
@@ -28,14 +26,14 @@
     }
 
     @Override
-    public void afterOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+    public void afterOperation(ILSMIndex index, LSMOperationType opType, ISearchOperationCallback searchCallback,
             IModificationOperationCallback modificationCallback) throws HyracksDataException {
         // The operation is considered inactive, immediately after leaving the index.
-        completeOperation(opType, searchCallback, modificationCallback);
+        completeOperation(index, opType, searchCallback, modificationCallback);
     }
 
     @Override
-    public void completeOperation(LSMOperationType opType, ISearchOperationCallback searchCallback,
+    public void completeOperation(ILSMIndex index, LSMOperationType opType, ISearchOperationCallback searchCallback,
             IModificationOperationCallback modificationCallback) throws HyracksDataException {
         // Flush will only be handled by last exiting thread.
         if (opType == LSMOperationType.MODIFICATION) {
diff --git a/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
new file mode 100644
index 0000000..1e0f34d
--- /dev/null
+++ b/hyracks/hyracks-storage-am-lsm-common/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
@@ -0,0 +1,330 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common.impls;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICacheMemoryAllocator;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
+import edu.uci.ics.hyracks.storage.common.file.IFileMapManager;
+import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
+
+public class VirtualBufferCache implements IVirtualBufferCache {
+    private static final int OVERFLOW_PADDING = 8;
+
+    private final ICacheMemoryAllocator allocator;
+    private final IFileMapManager fileMapManager;
+    private final int pageSize;
+    private final int numPages;
+
+    private final CacheBucket[] buckets;
+    private final ArrayList<VirtualPage> pages;
+
+    private int nextFree;
+
+    private boolean open;
+
+    public VirtualBufferCache(ICacheMemoryAllocator allocator, int pageSize, int numPages) {
+        this.allocator = allocator;
+        this.fileMapManager = new TransientFileMapManager();
+        this.pageSize = pageSize;
+        this.numPages = numPages;
+
+        buckets = new CacheBucket[numPages];
+        pages = new ArrayList<VirtualPage>();
+        nextFree = 0;
+        open = false;
+    }
+
+    @Override
+    public void createFile(FileReference fileRef) throws HyracksDataException {
+        synchronized (fileMapManager) {
+            if (fileMapManager.isMapped(fileRef)) {
+                throw new HyracksDataException("File " + fileRef + " is already mapped");
+            }
+            fileMapManager.registerFile(fileRef);
+        }
+    }
+
+    @Override
+    public void openFile(int fileId) throws HyracksDataException {
+    }
+
+    @Override
+    public void closeFile(int fileId) throws HyracksDataException {
+    }
+
+    @Override
+    public void deleteFile(int fileId, boolean flushDirtyPages) throws HyracksDataException {
+        synchronized (fileMapManager) {
+            if (!fileMapManager.isMapped(fileId)) {
+                throw new HyracksDataException("File with id " + fileId + " is not mapped");
+            }
+            fileMapManager.unregisterFile(fileId);
+        }
+
+        for (int i = 0; i < buckets.length; i++) {
+            CacheBucket bucket = buckets[i];
+            bucket.bucketLock.lock();
+            try {
+                VirtualPage prev = null;
+                VirtualPage curr = bucket.cachedPage;
+                while (curr != null) {
+                    if (BufferedFileHandle.getFileId(curr.dpid) == fileId) {
+                        if (prev == null) {
+                            bucket.cachedPage = curr.next;
+                            curr.reset();
+                            curr = bucket.cachedPage;
+                        } else {
+                            prev.next = curr.next;
+                            curr.reset();
+                            curr = prev.next;
+                        }
+                    } else {
+                        prev = curr;
+                        curr = curr.next;
+                    }
+                }
+            } finally {
+                bucket.bucketLock.unlock();
+            }
+        }
+        defragPageList();
+    }
+
+    private void defragPageList() {
+        synchronized (pages) {
+            int start = 0;
+            int end = nextFree - 1;
+            while (start < end) {
+                VirtualPage lastUsed = pages.get(end);
+                while (end > 0 && lastUsed.dpid == -1) {
+                    --end;
+                    lastUsed = pages.get(end);
+                }
+
+                if (end == 0) {
+                    nextFree = lastUsed.dpid == -1 ? 0 : 1;
+                    break;
+                }
+
+                VirtualPage firstUnused = pages.get(start);
+                while (start < end && firstUnused.dpid != -1) {
+                    ++start;
+                    firstUnused = pages.get(start);
+                }
+
+                if (start >= end) {
+                    break;
+                }
+
+                Collections.swap(pages, start, end);
+                nextFree = end;
+                --end;
+                ++start;
+            }
+        }
+    }
+
+    @Override
+    public ICachedPage tryPin(long dpid) throws HyracksDataException {
+        return pin(dpid, false);
+    }
+
+    @Override
+    public ICachedPage pin(long dpid, boolean newPage) throws HyracksDataException {
+        VirtualPage page = null;
+        int hash = hash(dpid);
+        CacheBucket bucket = buckets[hash];
+
+        bucket.bucketLock.lock();
+        try {
+            page = bucket.cachedPage;
+            while (page != null) {
+                if (page.dpid == dpid) {
+                    return page;
+                }
+                page = page.next;
+            }
+
+            if (!newPage) {
+                throw new HyracksDataException("Page " + BufferedFileHandle.getPageId(dpid)
+                        + " does not exist in file "
+                        + fileMapManager.lookupFileName(BufferedFileHandle.getFileId(dpid)));
+            }
+
+            page = getOrAllocPage(dpid);
+            page.next = bucket.cachedPage;
+            bucket.cachedPage = page;
+        } finally {
+            bucket.bucketLock.unlock();
+        }
+
+        return page;
+    }
+
+    private int hash(long dpid) {
+        return (int) (dpid % buckets.length);
+    }
+
+    private VirtualPage getOrAllocPage(long dpid) {
+        VirtualPage page = null;
+        synchronized (pages) {
+            if (nextFree >= pages.size()) {
+                page = new VirtualPage(allocator.allocate(pageSize, 1)[0]);
+                pages.add(page);
+            } else {
+                page = pages.get(nextFree);
+            }
+            ++nextFree;
+            page.dpid = dpid;
+        }
+        return page;
+    }
+
+    @Override
+    public void unpin(ICachedPage page) throws HyracksDataException {
+    }
+
+    @Override
+    public void flushDirtyPage(ICachedPage page) throws HyracksDataException {
+    }
+
+    @Override
+    public void force(int fileId, boolean metadata) throws HyracksDataException {
+    }
+
+    @Override
+    public int getPageSize() {
+        return pageSize;
+    }
+
+    @Override
+    public int getNumPages() {
+        return numPages;
+    }
+
+    @Override
+    public void open() {
+        if (open) {
+            return;
+        }
+        pages.trimToSize();
+        pages.ensureCapacity(numPages + OVERFLOW_PADDING);
+        ByteBuffer[] buffers = allocator.allocate(pageSize, numPages);
+        for (int i = 0; i < numPages; i++) {
+            pages.add(new VirtualPage(buffers[i]));
+            buckets[i] = new CacheBucket();
+        }
+        nextFree = 0;
+        open = true;
+    }
+
+    @Override
+    public void reset() {
+        for (int i = 0; i < numPages; i++) {
+            pages.get(i).reset();
+            buckets[i].cachedPage = null;
+        }
+        int excess = pages.size() - numPages;
+        if (excess > 0) {
+            for (int i = numPages + excess - 1; i >= numPages; i--) {
+                pages.remove(i);
+            }
+        }
+        nextFree = 0;
+    }
+
+    @Override
+    public void close() {
+        if (!open) {
+            return;
+        }
+
+        pages.clear();
+        for (int i = 0; i < numPages; i++) {
+            buckets[i].cachedPage = null;
+        }
+        open = false;
+    }
+
+    public String dumpState() {
+        StringBuilder sb = new StringBuilder();
+        sb.append(String.format("Page size = %d\n", pageSize));
+        sb.append(String.format("Capacity = %d\n", numPages));
+        sb.append(String.format("Allocated pages = %d\n", pages.size()));
+        sb.append(String.format("Next free page = %d\n", nextFree));
+        return sb.toString();
+    }
+
+    @Override
+    public IFileMapManager getFileMapProvider() {
+        return fileMapManager;
+    }
+
+    @Override
+    public boolean isFull() {
+        return nextFree >= numPages;
+    }
+
+    private static class CacheBucket {
+        private final ReentrantLock bucketLock;
+        private VirtualPage cachedPage;
+
+        public CacheBucket() {
+            this.bucketLock = new ReentrantLock();
+        }
+    }
+
+    private class VirtualPage implements ICachedPage {
+        final ByteBuffer buffer;
+        final ReadWriteLock latch;
+        volatile long dpid;
+        VirtualPage next;
+
+        public VirtualPage(ByteBuffer buffer) {
+            this.buffer = buffer;
+            latch = new ReentrantReadWriteLock(true);
+            dpid = -1;
+            next = null;
+        }
+
+        public void reset() {
+            dpid = -1;
+            next = null;
+        }
+
+        @Override
+        public ByteBuffer getBuffer() {
+            return buffer;
+        }
+
+        @Override
+        public void acquireReadLatch() {
+            latch.readLock().lock();
+        }
+
+        @Override
+        public void releaseReadLatch() {
+            latch.readLock().unlock();
+        }
+
+        @Override
+        public void acquireWriteLatch() {
+            latch.writeLock().lock();
+        }
+
+        @Override
+        public void releaseWriteLatch() {
+            latch.writeLock().unlock();
+        }
+
+    }
+}
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
index c97e10d..e0dd5b1 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelper.java
@@ -16,62 +16,51 @@
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.LSMInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.InvertedIndexUtils;
-import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public final class LSMInvertedIndexDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES,
-                DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy, opTrackerFactory, ioScheduler,
-                ioOpCallbackProvider);
+            IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
+                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
     }
 
     public LSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            int memPageSize, int memNumPages, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, bloomFilterFalsePositiveRate, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackProvider);
     }
 
     @Override
     public IIndex createIndexInstance() throws HyracksDataException {
         IInvertedIndexOperatorDescriptor invIndexOpDesc = (IInvertedIndexOperatorDescriptor) opDesc;
         try {
-            ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
-            IInMemoryBufferCache memBufferCache = new DualIndexInMemoryBufferCache(new HeapBufferAllocator(),
-                    memPageSize, memNumPages);
-            IInMemoryFreePageManager memFreePageManager = new DualIndexInMemoryFreePageManager(memNumPages,
-                    metaDataFrameFactory);
             IBufferCache diskBufferCache = opDesc.getStorageManager().getBufferCache(ctx);
             IFileMapProvider diskFileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
-            LSMInvertedIndex invIndex = InvertedIndexUtils.createLSMInvertedIndex(memBufferCache, memFreePageManager,
-                    diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(), invIndexOpDesc
-                            .getInvListsComparatorFactories(), invIndexOpDesc.getTokenTypeTraits(), invIndexOpDesc
-                            .getTokenComparatorFactories(), invIndexOpDesc.getTokenizerFactory(), diskBufferCache, ctx
-                            .getIOManager(), file.getFile().getPath(), bloomFilterFalsePositiveRate, mergePolicy,
-                    opTrackerFactory, ioScheduler, ioOpCallbackProvider,
+            LSMInvertedIndex invIndex = InvertedIndexUtils.createLSMInvertedIndex(virtualBufferCache,
+                    diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(),
+                    invIndexOpDesc.getInvListsComparatorFactories(), invIndexOpDesc.getTokenTypeTraits(),
+                    invIndexOpDesc.getTokenComparatorFactories(), invIndexOpDesc.getTokenizerFactory(),
+                    diskBufferCache, ctx.getIOManager(), file.getFile().getPath(), bloomFilterFalsePositiveRate,
+                    mergePolicy, opTrackerFactory.createOperationTracker(ctx), ioScheduler, ioOpCallbackProvider,
                     opDesc.getFileSplitProvider().getFileSplits()[partition].getIODeviceId());
             return invIndex;
         } catch (IndexException e) {
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
index 60a0b47..6a8da23 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexDataflowHelperFactory.java
@@ -21,27 +21,29 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 
 public class LSMInvertedIndexDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
 
     private static final long serialVersionUID = 1L;
 
-    public LSMInvertedIndexDataflowHelperFactory(ILSMMergePolicyProvider mergePolicyProvider,
-            ILSMOperationTrackerFactory opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider, int memPageSize, int memNumPages,
+    public LSMInvertedIndexDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             double bloomFilterFalsePositiveRate) {
-        super(mergePolicyProvider, opTrackerProvider, ioSchedulerProvider, ioOpCallbackProvider, memPageSize,
-                memNumPages, bloomFilterFalsePositiveRate);
+        super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider,
+                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        return new LSMInvertedIndexDataflowHelper(opDesc, ctx, partition, memPageSize, memNumPages,
-                bloomFilterFalsePositiveRate, mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory,
-                ioSchedulerProvider.getIOScheduler(ctx), ioOpCallbackProvider);
+        return new LSMInvertedIndexDataflowHelper(opDesc, ctx, partition,
+                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
+                ioOpCallbackProvider);
     }
 
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexInsertUpdateDeleteOperator.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexInsertUpdateDeleteOperator.java
index 3122aa0..768d4a8 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexInsertUpdateDeleteOperator.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/LSMInvertedIndexInsertUpdateDeleteOperator.java
@@ -38,8 +38,8 @@
 
     private static final long serialVersionUID = 1L;
 
-    private final int[] fieldPermutation;
-    private final IndexOperation op;
+    protected final int[] fieldPermutation;
+    protected final IndexOperation op;
 
     public LSMInvertedIndexInsertUpdateDeleteOperator(IOperatorDescriptorRegistry spec, RecordDescriptor recDesc,
             IStorageManagerInterface storageManager, IFileSplitProvider fileSplitProvider,
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java
index 6c5b25f..f2c2aff 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelper.java
@@ -16,62 +16,51 @@
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls.PartitionedLSMInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.util.InvertedIndexUtils;
-import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public final class PartitionedLSMInvertedIndexDataflowHelper extends AbstractLSMIndexDataflowHelper {
 
     public PartitionedLSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition, ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES,
-                DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy, opTrackerFactory, ioScheduler,
-                ioOpCallbackProvider);
+            int partition, IVirtualBufferCache virtualBufferCache, ILSMMergePolicy mergePolicy,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, mergePolicy,
+                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
     }
 
     public PartitionedLSMInvertedIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition, int memPageSize, int memNumPages, double bloomFilterFalsePositiveRate,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            int partition, IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, bloomFilterFalsePositiveRate, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackProvider);
     }
 
     @Override
     public IIndex createIndexInstance() throws HyracksDataException {
         IInvertedIndexOperatorDescriptor invIndexOpDesc = (IInvertedIndexOperatorDescriptor) opDesc;
         try {
-            ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
-            IInMemoryBufferCache memBufferCache = new DualIndexInMemoryBufferCache(new HeapBufferAllocator(),
-                    memPageSize, memNumPages);
-            IInMemoryFreePageManager memFreePageManager = new DualIndexInMemoryFreePageManager(memNumPages,
-                    metaDataFrameFactory);
             IBufferCache diskBufferCache = opDesc.getStorageManager().getBufferCache(ctx);
             IFileMapProvider diskFileMapProvider = opDesc.getStorageManager().getFileMapProvider(ctx);
-            PartitionedLSMInvertedIndex invIndex = InvertedIndexUtils.createPartitionedLSMInvertedIndex(memBufferCache,
-                    memFreePageManager, diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(), invIndexOpDesc
-                            .getInvListsComparatorFactories(), invIndexOpDesc.getTokenTypeTraits(), invIndexOpDesc
-                            .getTokenComparatorFactories(), invIndexOpDesc.getTokenizerFactory(), diskBufferCache, ctx
-                            .getIOManager(), file.getFile().getPath(), bloomFilterFalsePositiveRate, mergePolicy,
-                    opTrackerFactory, ioScheduler, ioOpCallbackProvider,
+            PartitionedLSMInvertedIndex invIndex = InvertedIndexUtils.createPartitionedLSMInvertedIndex(
+                    virtualBufferCache, diskFileMapProvider, invIndexOpDesc.getInvListsTypeTraits(),
+                    invIndexOpDesc.getInvListsComparatorFactories(), invIndexOpDesc.getTokenTypeTraits(),
+                    invIndexOpDesc.getTokenComparatorFactories(), invIndexOpDesc.getTokenizerFactory(),
+                    diskBufferCache, ctx.getIOManager(), file.getFile().getPath(), bloomFilterFalsePositiveRate,
+                    mergePolicy, opTrackerFactory.createOperationTracker(ctx), ioScheduler, ioOpCallbackProvider,
                     opDesc.getFileSplitProvider().getFileSplits()[partition].getIODeviceId());
             return invIndex;
         } catch (IndexException e) {
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java
index 801462b..c1b55d0 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/dataflow/PartitionedLSMInvertedIndexDataflowHelperFactory.java
@@ -21,26 +21,28 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 
 public class PartitionedLSMInvertedIndexDataflowHelperFactory extends AbstractLSMIndexDataflowHelperFactory {
 
     private static final long serialVersionUID = 1L;
 
-    public PartitionedLSMInvertedIndexDataflowHelperFactory(ILSMMergePolicyProvider mergePolicyProvider,
-            ILSMOperationTrackerFactory opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
-            ILSMIOOperationCallbackProvider ioOpCallbackProvider, int memPageSize, int memNumPages,
+    public PartitionedLSMInvertedIndexDataflowHelperFactory(IVirtualBufferCacheProvider virtualBufferCacheProvider,
+            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerProvider opTrackerProvider,
+            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             double bloomFilterFalsePositiveRate) {
-        super(mergePolicyProvider, opTrackerProvider, ioSchedulerProvider, ioOpCallbackProvider, memNumPages,
-                memNumPages, bloomFilterFalsePositiveRate);
+        super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerProvider, ioSchedulerProvider,
+                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
     }
 
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        return new PartitionedLSMInvertedIndexDataflowHelper(opDesc, ctx, partition, memPageSize, memNumPages,
-                bloomFilterFalsePositiveRate, mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory,
-                ioSchedulerProvider.getIOScheduler(ctx), ioOpCallbackProvider);
+        return new PartitionedLSMInvertedIndexDataflowHelper(opDesc, ctx, partition,
+                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
+                ioOpCallbackProvider);
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
index beb4dc9..e9da22f 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndex.java
@@ -34,7 +34,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.btree.util.BTreeUtils;
 import edu.uci.ics.hyracks.storage.am.common.api.ICursorInitialState;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
@@ -42,13 +41,13 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchPredicate;
+import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
 import edu.uci.ics.hyracks.storage.am.common.tuples.PermutingTupleReference;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponentFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
@@ -60,8 +59,9 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractLSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallbackWrapper;
@@ -82,7 +82,7 @@
 
     // In-memory components.
     protected final LSMInvertedIndexMutableComponent mutableComponent;
-    protected final IInMemoryFreePageManager memFreePageManager;
+    protected final IVirtualFreePageManager virtualFreePageManager;
     protected final IBinaryTokenizerFactory tokenizerFactory;
 
     // On-disk components.
@@ -95,29 +95,29 @@
     protected final ITypeTraits[] tokenTypeTraits;
     protected final IBinaryComparatorFactory[] tokenCmpFactories;
 
-    public LSMInvertedIndex(IInMemoryBufferCache memBufferCache, IInMemoryFreePageManager memFreePageManager,
-            OnDiskInvertedIndexFactory diskInvIndexFactory, BTreeFactory deletedKeysBTreeFactory,
-            BloomFilterFactory bloomFilterFactory, double bloomFilterFalsePositiveRate,
-            ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
+    public LSMInvertedIndex(IVirtualBufferCache virtualBufferCache, OnDiskInvertedIndexFactory diskInvIndexFactory,
+            BTreeFactory deletedKeysBTreeFactory, BloomFilterFactory bloomFilterFactory,
+            double bloomFilterFalsePositiveRate, ILSMIndexFileManager fileManager,
+            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
             IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider)
-            throws IndexException {
-        super(memFreePageManager, diskInvIndexFactory.getBufferCache(), fileManager, diskFileMapProvider,
-                bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
-        this.memFreePageManager = memFreePageManager;
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
+        super(virtualBufferCache, diskInvIndexFactory.getBufferCache(), fileManager, diskFileMapProvider,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
+        this.virtualFreePageManager = new VirtualFreePageManager(virtualBufferCache.getNumPages());
         this.tokenizerFactory = tokenizerFactory;
         this.invListTypeTraits = invListTypeTraits;
         this.invListCmpFactories = invListCmpFactories;
         this.tokenTypeTraits = tokenTypeTraits;
         this.tokenCmpFactories = tokenCmpFactories;
         // Create in-memory component.
-        InMemoryInvertedIndex memInvIndex = createInMemoryInvertedIndex(memBufferCache);
-        BTree deleteKeysBTree = BTreeUtils.createBTree(memBufferCache, memFreePageManager,
-                ((InMemoryBufferCache) memBufferCache).getFileMapProvider(), invListTypeTraits, invListCmpFactories,
-                BTreeLeafFrameType.REGULAR_NSM, new FileReference(new File("membtree")));
-        mutableComponent = new LSMInvertedIndexMutableComponent(memInvIndex, deleteKeysBTree, memFreePageManager);
+        InMemoryInvertedIndex memInvIndex = createInMemoryInvertedIndex(virtualBufferCache);
+        BTree deleteKeysBTree = BTreeUtils.createBTree(virtualBufferCache, new VirtualFreePageManager(
+                virtualBufferCache.getNumPages()), ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(),
+                invListTypeTraits, invListCmpFactories, BTreeLeafFrameType.REGULAR_NSM, new FileReference(new File(
+                        fileManager.getBaseDir() + "_virtual_del")));
+        mutableComponent = new LSMInvertedIndexMutableComponent(memInvIndex, deleteKeysBTree, virtualBufferCache);
         componentFactory = new LSMInvertedIndexComponentFactory(diskInvIndexFactory, deletedKeysBTreeFactory,
                 bloomFilterFactory);
     }
@@ -138,9 +138,10 @@
         if (isActivated) {
             return;
         }
+
         try {
             List<ILSMComponent> immutableComponents = componentsRef.get();
-            ((InMemoryBufferCache) mutableComponent.getInvIndex().getBufferCache()).open();
+            ((IVirtualBufferCache) mutableComponent.getInvIndex().getBufferCache()).open();
             mutableComponent.getInvIndex().create();
             mutableComponent.getInvIndex().activate();
             mutableComponent.getDeletedKeysBTree().create();
@@ -193,7 +194,6 @@
         }
 
         isActivated = false;
-
         if (flushOnExit) {
             BlockingIOOperationCallbackWrapper blockingCallBack = new BlockingIOOperationCallbackWrapper(
                     ioOpCallbackProvider.getIOOperationCallback(this));
@@ -218,7 +218,7 @@
         mutableComponent.getDeletedKeysBTree().deactivate();
         mutableComponent.getInvIndex().destroy();
         mutableComponent.getDeletedKeysBTree().destroy();
-        ((InMemoryBufferCache) mutableComponent.getInvIndex().getBufferCache()).close();
+        ((IVirtualBufferCache) mutableComponent.getInvIndex().getBufferCache()).close();
     }
 
     @Override
@@ -619,10 +619,11 @@
         }
     }
 
-    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IInMemoryBufferCache memBufferCache)
+    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IVirtualBufferCache virtualBufferCache)
             throws IndexException {
-        return InvertedIndexUtils.createInMemoryBTreeInvertedindex(memBufferCache, memFreePageManager,
-                invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory);
+        return InvertedIndexUtils.createInMemoryBTreeInvertedindex(virtualBufferCache, virtualFreePageManager,
+                invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory,
+                new FileReference(new File(fileManager.getBaseDir() + "_virtual_vocab")));
     }
 
     protected LSMInvertedIndexImmutableComponent createDiskInvIndexComponent(ILSMComponentFactory factory,
@@ -679,8 +680,8 @@
 
     @Override
     public long getMemoryAllocationSize() {
-        InMemoryBufferCache memBufferCache = (InMemoryBufferCache) mutableComponent.getInvIndex().getBufferCache();
-        return memBufferCache.getNumPages() * memBufferCache.getPageSize();
+        IBufferCache virtualBufferCache = mutableComponent.getInvIndex().getBufferCache();
+        return virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMutableComponent.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMutableComponent.java
index 615f1ee..a2bf110 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexMutableComponent.java
@@ -17,7 +17,7 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMutableLSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
 
@@ -25,13 +25,12 @@
 
     private final IInvertedIndex invIndex;
     private final BTree deletedKeysBTree;
-    private final IInMemoryFreePageManager mfpm;
+    private final IVirtualBufferCache vbc;
 
-    public LSMInvertedIndexMutableComponent(IInvertedIndex invIndex, BTree deletedKeysBTree,
-            IInMemoryFreePageManager mfpm) {
+    public LSMInvertedIndexMutableComponent(IInvertedIndex invIndex, BTree deletedKeysBTree, IVirtualBufferCache vbc) {
         this.invIndex = invIndex;
         this.deletedKeysBTree = deletedKeysBTree;
-        this.mfpm = mfpm;
+        this.vbc = vbc;
     }
 
     public IInvertedIndex getInvIndex() {
@@ -44,13 +43,19 @@
 
     @Override
     protected boolean isFull() {
-        return mfpm.isFull();
+        return vbc.isFull();
     }
 
     @Override
     protected void reset() throws HyracksDataException {
         super.reset();
-        invIndex.clear();
-        deletedKeysBTree.clear();
+        invIndex.deactivate();
+        invIndex.destroy();
+        invIndex.create();
+        invIndex.activate();
+        deletedKeysBTree.deactivate();
+        deletedKeysBTree.destroy();
+        deletedKeysBTree.create();
+        deletedKeysBTree.activate();
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java
index 36ad51b..260ddc2 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/LSMInvertedIndexSearchCursor.java
@@ -165,18 +165,29 @@
 
     @Override
     public void close() throws HyracksDataException {
-        reset();
-        accessorIndex = -1;
-        harness.endSearch(opCtx);
+        try {
+            reset();
+            accessorIndex = -1;
+        } finally {
+            if (harness != null) {
+                harness.endSearch(opCtx);
+            }
+        }
     }
 
     @Override
     public void reset() throws HyracksDataException {
-        if (currentCursor != null) {
-            currentCursor.close();
-            currentCursor = null;
+        try {
+            if (currentCursor != null) {
+                currentCursor.close();
+                currentCursor = null;
+            }
+            accessorIndex = 0;
+        } finally {
+            if (harness != null) {
+                harness.endSearch(opCtx);
+            }
         }
-        accessorIndex = 0;
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java
index a45f729..2c579ab 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/impls/PartitionedLSMInvertedIndex.java
@@ -15,17 +15,19 @@
 
 package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.impls;
 
+import java.io.File;
+
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
+import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.storage.am.bloomfilter.impls.BloomFilterFactory;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.inmemory.InMemoryInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.ondisk.OnDiskInvertedIndexFactory;
@@ -35,26 +37,25 @@
 
 public class PartitionedLSMInvertedIndex extends LSMInvertedIndex {
 
-    public PartitionedLSMInvertedIndex(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, OnDiskInvertedIndexFactory diskInvIndexFactory,
-            BTreeFactory deletedKeysBTreeFactory, BloomFilterFactory bloomFilterFactory,
-            double bloomFilterFalsePositiveRate, ILSMIndexFileManager fileManager,
-            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
+    public PartitionedLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
+            OnDiskInvertedIndexFactory diskInvIndexFactory, BTreeFactory deletedKeysBTreeFactory,
+            BloomFilterFactory bloomFilterFactory, double bloomFilterFalsePositiveRate,
+            ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
             IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider)
-            throws IndexException {
-        super(memBufferCache, memFreePageManager, diskInvIndexFactory, deletedKeysBTreeFactory, bloomFilterFactory,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
+        super(virtualBufferCache, diskInvIndexFactory, deletedKeysBTreeFactory, bloomFilterFactory,
                 bloomFilterFalsePositiveRate, fileManager, diskFileMapProvider, invListTypeTraits, invListCmpFactories,
-                tokenTypeTraits, tokenCmpFactories, tokenizerFactory, mergePolicy, opTrackerFactory, ioScheduler,
+                tokenTypeTraits, tokenCmpFactories, tokenizerFactory, mergePolicy, opTracker, ioScheduler,
                 ioOpCallbackProvider);
     }
 
-    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IInMemoryBufferCache memBufferCache)
+    protected InMemoryInvertedIndex createInMemoryInvertedIndex(IVirtualBufferCache virtualBufferCache)
             throws IndexException {
-        return InvertedIndexUtils.createPartitionedInMemoryBTreeInvertedindex(memBufferCache, memFreePageManager,
-                invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory);
+        return InvertedIndexUtils.createPartitionedInMemoryBTreeInvertedindex(virtualBufferCache,
+                virtualFreePageManager, invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories,
+                tokenizerFactory, new FileReference(new File(fileManager.getBaseDir() + "_virtual_vocab")));
     }
 
 }
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java
index d5a074e..8728240 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/InMemoryInvertedIndex.java
@@ -14,8 +14,6 @@
  */
 package edu.uci.ics.hyracks.storage.am.lsm.invertedindex.inmemory;
 
-import java.io.File;
-
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
@@ -36,7 +34,7 @@
 import edu.uci.ics.hyracks.storage.am.common.api.ISearchOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListCursor;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.tokenizers.IBinaryTokenizerFactory;
@@ -45,7 +43,6 @@
 public class InMemoryInvertedIndex implements IInvertedIndex {
 
     protected final BTree btree;
-    protected final FileReference memBTreeFile = new FileReference(new File("memBTree"));
     protected final ITypeTraits[] tokenTypeTraits;
     protected final IBinaryComparatorFactory[] tokenCmpFactories;
     protected final ITypeTraits[] invListTypeTraits;
@@ -55,10 +52,10 @@
     protected final ITypeTraits[] btreeTypeTraits;
     protected final IBinaryComparatorFactory[] btreeCmpFactories;
 
-    public InMemoryInvertedIndex(IBufferCache memBufferCache, IFreePageManager memFreePageManager,
+    public InMemoryInvertedIndex(IBufferCache virtualBufferCache, IFreePageManager virtualFreePageManager,
             ITypeTraits[] invListTypeTraits, IBinaryComparatorFactory[] invListCmpFactories,
             ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenCmpFactories,
-            IBinaryTokenizerFactory tokenizerFactory) throws BTreeException {
+            IBinaryTokenizerFactory tokenizerFactory, FileReference btreeFileRef) throws BTreeException {
         this.tokenTypeTraits = tokenTypeTraits;
         this.tokenCmpFactories = tokenCmpFactories;
         this.invListTypeTraits = invListTypeTraits;
@@ -76,9 +73,9 @@
             btreeTypeTraits[tokenTypeTraits.length + i] = invListTypeTraits[i];
             btreeCmpFactories[tokenTypeTraits.length + i] = invListCmpFactories[i];
         }
-        this.btree = BTreeUtils.createBTree(memBufferCache, memFreePageManager,
-                ((InMemoryBufferCache) memBufferCache).getFileMapProvider(), btreeTypeTraits, btreeCmpFactories,
-                BTreeLeafFrameType.REGULAR_NSM, memBTreeFile);
+        this.btree = BTreeUtils.createBTree(virtualBufferCache, virtualFreePageManager,
+                ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(), btreeTypeTraits, btreeCmpFactories,
+                BTreeLeafFrameType.REGULAR_NSM, btreeFileRef);
     }
 
     @Override
@@ -145,8 +142,8 @@
 
     @Override
     public long getMemoryAllocationSize() {
-        InMemoryBufferCache memBufferCache = (InMemoryBufferCache) btree.getBufferCache();
-        return memBufferCache.getNumPages() * memBufferCache.getPageSize();
+        IBufferCache virtualBufferCache = btree.getBufferCache();
+        return virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/PartitionedInMemoryInvertedIndex.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/PartitionedInMemoryInvertedIndex.java
index 7c3f4e4..b57e976 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/PartitionedInMemoryInvertedIndex.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/inmemory/PartitionedInMemoryInvertedIndex.java
@@ -20,6 +20,7 @@
 import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeAccessor;
@@ -48,9 +49,9 @@
     public PartitionedInMemoryInvertedIndex(IBufferCache memBufferCache, IFreePageManager memFreePageManager,
             ITypeTraits[] invListTypeTraits, IBinaryComparatorFactory[] invListCmpFactories,
             ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenCmpFactories,
-            IBinaryTokenizerFactory tokenizerFactory) throws BTreeException {
+            IBinaryTokenizerFactory tokenizerFactory, FileReference btreeFileRef) throws BTreeException {
         super(memBufferCache, memFreePageManager, invListTypeTraits, invListCmpFactories, tokenTypeTraits,
-                tokenCmpFactories, tokenizerFactory);
+                tokenCmpFactories, tokenizerFactory, btreeFileRef);
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
index 06be7aa..63d44ac 100644
--- a/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
+++ b/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/InvertedIndexUtils.java
@@ -27,18 +27,17 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeNSMInteriorFrameFactory;
 import edu.uci.ics.hyracks.storage.am.btree.util.BTreeUtils;
 import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.freepage.LinkedListFreePageManagerFactory;
 import edu.uci.ics.hyracks.storage.am.common.tuples.TypeAwareTupleWriterFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListBuilder;
 import edu.uci.ics.hyracks.storage.am.lsm.invertedindex.api.IInvertedListBuilderFactory;
@@ -60,21 +59,21 @@
 public class InvertedIndexUtils {
 
     public static InMemoryInvertedIndex createInMemoryBTreeInvertedindex(IBufferCache memBufferCache,
-            IFreePageManager memFreePageManager, ITypeTraits[] invListTypeTraits,
+            IFreePageManager virtualFreePageManager, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
-            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory)
-            throws BTreeException {
-        return new InMemoryInvertedIndex(memBufferCache, memFreePageManager, invListTypeTraits, invListCmpFactories,
-                tokenTypeTraits, tokenCmpFactories, tokenizerFactory);
+            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
+            FileReference btreeFileRef) throws BTreeException {
+        return new InMemoryInvertedIndex(memBufferCache, virtualFreePageManager, invListTypeTraits,
+                invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory, btreeFileRef);
     }
 
     public static InMemoryInvertedIndex createPartitionedInMemoryBTreeInvertedindex(IBufferCache memBufferCache,
-            IFreePageManager memFreePageManager, ITypeTraits[] invListTypeTraits,
+            IFreePageManager virtualFreePageManager, ITypeTraits[] invListTypeTraits,
             IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
-            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory)
-            throws BTreeException {
-        return new PartitionedInMemoryInvertedIndex(memBufferCache, memFreePageManager, invListTypeTraits,
-                invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory);
+            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
+            FileReference btreeFileRef) throws BTreeException {
+        return new PartitionedInMemoryInvertedIndex(memBufferCache, virtualFreePageManager, invListTypeTraits,
+                invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory, btreeFileRef);
     }
 
     public static OnDiskInvertedIndex createOnDiskInvertedIndex(IBufferCache bufferCache,
@@ -117,13 +116,24 @@
         return deletedKeysBTreeFactory;
     }
 
-    public static LSMInvertedIndex createLSMInvertedIndex(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IFileMapProvider diskFileMapProvider,
-            ITypeTraits[] invListTypeTraits, IBinaryComparatorFactory[] invListCmpFactories,
-            ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenCmpFactories,
-            IBinaryTokenizerFactory tokenizerFactory, IBufferCache diskBufferCache, IIOManager ioManager,
-            String onDiskDir, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+    public static LSMInvertedIndex createLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
+            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
+            IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
+            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
+            IBufferCache diskBufferCache, IIOManager ioManager, String onDiskDir, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
+        return createLSMInvertedIndex(virtualBufferCache, diskFileMapProvider, invListTypeTraits, invListCmpFactories,
+                tokenTypeTraits, tokenCmpFactories, tokenizerFactory, diskBufferCache, ioManager, onDiskDir,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider, 0);
+    }
+
+    public static LSMInvertedIndex createLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
+            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
+            IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
+            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
+            IBufferCache diskBufferCache, IIOManager ioManager, String onDiskDir, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider, int ioDeviceId) throws IndexException {
 
         BTreeFactory deletedKeysBTreeFactory = createDeletedKeysBTreeFactory(diskFileMapProvider, invListTypeTraits,
@@ -146,20 +156,31 @@
                 diskFileMapProvider, invListBuilderFactory, invListTypeTraits, invListCmpFactories, tokenTypeTraits,
                 tokenCmpFactories, fileManager);
 
-        LSMInvertedIndex invIndex = new LSMInvertedIndex(memBufferCache, memFreePageManager, invIndexFactory,
-                deletedKeysBTreeFactory, bloomFilterFactory, bloomFilterFalsePositiveRate, fileManager,
-                diskFileMapProvider, invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories,
-                tokenizerFactory, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        LSMInvertedIndex invIndex = new LSMInvertedIndex(virtualBufferCache, invIndexFactory, deletedKeysBTreeFactory,
+                bloomFilterFactory, bloomFilterFalsePositiveRate, fileManager, diskFileMapProvider, invListTypeTraits,
+                invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory, mergePolicy, opTracker,
+                ioScheduler, ioOpCallbackProvider);
         return invIndex;
     }
 
-    public static PartitionedLSMInvertedIndex createPartitionedLSMInvertedIndex(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IFileMapProvider diskFileMapProvider,
-            ITypeTraits[] invListTypeTraits, IBinaryComparatorFactory[] invListCmpFactories,
-            ITypeTraits[] tokenTypeTraits, IBinaryComparatorFactory[] tokenCmpFactories,
-            IBinaryTokenizerFactory tokenizerFactory, IBufferCache diskBufferCache, IIOManager ioManager,
-            String onDiskDir, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+    public static PartitionedLSMInvertedIndex createPartitionedLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
+            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
+            IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
+            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
+            IBufferCache diskBufferCache, IIOManager ioManager, String onDiskDir, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) throws IndexException {
+        return createPartitionedLSMInvertedIndex(virtualBufferCache, diskFileMapProvider, invListTypeTraits,
+                invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory, diskBufferCache, ioManager,
+                onDiskDir, bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider, 0);
+    }
+
+    public static PartitionedLSMInvertedIndex createPartitionedLSMInvertedIndex(IVirtualBufferCache virtualBufferCache,
+            IFileMapProvider diskFileMapProvider, ITypeTraits[] invListTypeTraits,
+            IBinaryComparatorFactory[] invListCmpFactories, ITypeTraits[] tokenTypeTraits,
+            IBinaryComparatorFactory[] tokenCmpFactories, IBinaryTokenizerFactory tokenizerFactory,
+            IBufferCache diskBufferCache, IIOManager ioManager, String onDiskDir, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider, int ioDeviceId) throws IndexException {
 
         BTreeFactory deletedKeysBTreeFactory = createDeletedKeysBTreeFactory(diskFileMapProvider, invListTypeTraits,
@@ -182,10 +203,10 @@
                 diskBufferCache, diskFileMapProvider, invListBuilderFactory, invListTypeTraits, invListCmpFactories,
                 tokenTypeTraits, tokenCmpFactories, fileManager);
 
-        PartitionedLSMInvertedIndex invIndex = new PartitionedLSMInvertedIndex(memBufferCache, memFreePageManager,
-                invIndexFactory, deletedKeysBTreeFactory, bloomFilterFactory, bloomFilterFalsePositiveRate,
-                fileManager, diskFileMapProvider, invListTypeTraits, invListCmpFactories, tokenTypeTraits,
-                tokenCmpFactories, tokenizerFactory, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        PartitionedLSMInvertedIndex invIndex = new PartitionedLSMInvertedIndex(virtualBufferCache, invIndexFactory,
+                deletedKeysBTreeFactory, bloomFilterFactory, bloomFilterFalsePositiveRate, fileManager,
+                diskFileMapProvider, invListTypeTraits, invListCmpFactories, tokenTypeTraits, tokenCmpFactories,
+                tokenizerFactory, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
         return invIndex;
     }
 }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
index 5fcdcea..3e8dba5 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/AbstractLSMRTreeDataflowHelper.java
@@ -22,23 +22,18 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IIOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.AbstractTreeIndexOperatorDescriptor;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelper;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
-import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
@@ -50,25 +45,25 @@
     protected final ILinearizeComparatorFactory linearizeCmpFactory;
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IBinaryComparatorFactory[] btreeComparatorFactories,
+            IVirtualBufferCache virtualBufferCache, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        this(opDesc, ctx, partition, DEFAULT_MEM_PAGE_SIZE, DEFAULT_MEM_NUM_PAGES,
-                DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE, btreeComparatorFactories, valueProviderFactories,
-                rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
+        this(opDesc, ctx, partition, virtualBufferCache, DEFAULT_BLOOM_FILTER_FALSE_POSITIVE_RATE,
+                btreeComparatorFactories, valueProviderFactories, rtreePolicyType, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
     }
 
     public AbstractLSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            int memPageSize, int memNumPages, double bloomFilterFalsePositiveRate,
+            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, bloomFilterFalsePositiveRate, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
+                ioScheduler, ioOpCallbackProvider);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
@@ -78,22 +73,18 @@
     @Override
     public ITreeIndex createIndexInstance() throws HyracksDataException {
         AbstractTreeIndexOperatorDescriptor treeOpDesc = (AbstractTreeIndexOperatorDescriptor) opDesc;
-        ITreeIndexMetaDataFrameFactory metaDataFrameFactory = new LIFOMetaDataFrameFactory();
-        IInMemoryBufferCache memBufferCache = new DualIndexInMemoryBufferCache(new HeapBufferAllocator(), memPageSize,
-                memNumPages);
-        IInMemoryFreePageManager memFreePageManager = new DualIndexInMemoryFreePageManager(memNumPages,
-                metaDataFrameFactory);
-        return createLSMTree(memBufferCache, memFreePageManager, ctx.getIOManager(), file, opDesc.getStorageManager()
-                .getBufferCache(ctx), opDesc.getStorageManager().getFileMapProvider(ctx),
+        return createLSMTree(virtualBufferCache, ctx.getIOManager(), file,
+                opDesc.getStorageManager().getBufferCache(ctx), opDesc.getStorageManager().getFileMapProvider(ctx),
                 treeOpDesc.getTreeIndexTypeTraits(), treeOpDesc.getTreeIndexComparatorFactories(),
-                btreeComparatorFactories, valueProviderFactories, rtreePolicyType, linearizeCmpFactory, partition);
+                btreeComparatorFactories, opTrackerFactory.createOperationTracker(ctx), valueProviderFactories,
+                rtreePolicyType, linearizeCmpFactory, partition);
 
     }
 
-    protected abstract ITreeIndex createLSMTree(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
-            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
+    protected abstract ITreeIndex createLSMTree(IVirtualBufferCache virtualBufferCache, IIOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, ILSMOperationTracker opTracker,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILinearizeComparatorFactory linearizeCmpFactory, int startIODeviceIndex) throws HyracksDataException;
 }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
index 5ab5513..80a56c6 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelper.java
@@ -22,16 +22,16 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IIOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
@@ -40,38 +40,38 @@
 public class LSMRTreeDataflowHelper extends AbstractLSMRTreeDataflowHelper {
 
     public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            IBinaryComparatorFactory[] btreeComparatorFactories,
+            IVirtualBufferCache virtualBufferCache, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
+        super(opDesc, ctx, partition, virtualBufferCache, btreeComparatorFactories, valueProviderFactories,
+                rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
     }
 
     public LSMRTreeDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx, int partition,
-            int memPageSize, int memNumPages, double bloomFilterFalsePositiveRate,
+            IVirtualBufferCache virtualBufferCache, double bloomFilterFalsePositiveRate,
             IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, bloomFilterFalsePositiveRate, btreeComparatorFactories,
+        super(opDesc, ctx, partition, virtualBufferCache, bloomFilterFalsePositiveRate, btreeComparatorFactories,
                 valueProviderFactories, rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler,
                 ioOpCallbackProvider, linearizeCmpFactory);
     }
 
     @Override
-    protected ITreeIndex createLSMTree(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
-            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
+    protected ITreeIndex createLSMTree(IVirtualBufferCache virtualBufferCache, IIOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, ILSMOperationTracker opTracker,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILinearizeComparatorFactory linearizeCmpFactory, int startIODeviceIndex) throws HyracksDataException {
         try {
-            return LSMRTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file, diskBufferCache,
+            return LSMRTreeUtils.createLSMTree(virtualBufferCache, ioManager, file, diskBufferCache,
                     diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories, valueProviderFactories,
-                    rtreePolicyType, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory, ioScheduler,
+                    rtreePolicyType, bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler,
                     ioOpCallbackProvider, linearizeCmpFactory,
                     opDesc.getFileSplitProvider().getFileSplits()[partition].getIODeviceId());
         } catch (TreeIndexException e) {
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
index 0778e15..befbc3c 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeDataflowHelperFactory.java
@@ -24,7 +24,8 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.dataflow.AbstractLSMIndexDataflowHelperFactory;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 
@@ -39,12 +40,12 @@
 
     public LSMRTreeDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
-            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
-            ILinearizeComparatorFactory linearizeCmpFactory, int memPageSize, int memNumPages,
+            IVirtualBufferCacheProvider virtualBufferCacheProvider, ILSMMergePolicyProvider mergePolicyProvider,
+            ILSMOperationTrackerProvider opTrackerFactory, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizeCmpFactory,
             double bloomFilterFalsePositiveRate) {
-        super(mergePolicyProvider, opTrackerFactory, ioSchedulerProvider, ioOpCallbackProvider, memPageSize,
-                memNumPages, bloomFilterFalsePositiveRate);
+        super(virtualBufferCacheProvider, mergePolicyProvider, opTrackerFactory, ioSchedulerProvider,
+                ioOpCallbackProvider, bloomFilterFalsePositiveRate);
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
@@ -54,8 +55,9 @@
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        return new LSMRTreeDataflowHelper(opDesc, ctx, partition, memPageSize, memNumPages,
-                bloomFilterFalsePositiveRate, btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
+        return new LSMRTreeDataflowHelper(opDesc, ctx, partition,
+                virtualBufferCacheProvider.getVirtualBufferCache(ctx), bloomFilterFalsePositiveRate,
+                btreeComparatorFactories, valueProviderFactories, rtreePolicyType,
                 mergePolicyProvider.getMergePolicy(ctx), opTrackerFactory, ioSchedulerProvider.getIOScheduler(ctx),
                 ioOpCallbackProvider, linearizeCmpFactory);
     }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
index d4fac8f..0a309ff 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelper.java
@@ -22,16 +22,16 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IIOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.dataflow.IIndexOperatorDescriptor;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
@@ -39,37 +39,27 @@
 
 public class LSMRTreeWithAntiMatterTuplesDataflowHelper extends AbstractLSMRTreeDataflowHelper {
     public LSMRTreeWithAntiMatterTuplesDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition, IBinaryComparatorFactory[] btreeComparatorFactories,
+            int partition, IVirtualBufferCache virtualBufferCache, IBinaryComparatorFactory[] btreeComparatorFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
+            ILSMMergePolicy mergePolicy, ILSMOperationTrackerProvider opTrackerFactory,
             ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
             ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, btreeComparatorFactories, valueProviderFactories, rtreePolicyType, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
-    }
-
-    public LSMRTreeWithAntiMatterTuplesDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
-            int partition, int memPageSize, int memNumPages, IBinaryComparatorFactory[] btreeComparatorFactories,
-            IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
-            ILinearizeComparatorFactory linearizeCmpFactory) {
-        super(opDesc, ctx, partition, memPageSize, memNumPages, 0, btreeComparatorFactories, valueProviderFactories,
+        super(opDesc, ctx, partition, virtualBufferCache, btreeComparatorFactories, valueProviderFactories,
                 rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider, linearizeCmpFactory);
     }
 
     @Override
-    protected ITreeIndex createLSMTree(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
-            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
+    protected ITreeIndex createLSMTree(IVirtualBufferCache virtualBufferCache, IIOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, ILSMOperationTracker opTracker,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
             ILinearizeComparatorFactory linearizeCmpFactory, int startIODeviceIndex) throws HyracksDataException {
         try {
-            return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(memBufferCache, memFreePageManager, ioManager, file,
+            return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(virtualBufferCache, ioManager, file,
                     diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                    valueProviderFactories, rtreePolicyType, mergePolicy, opTrackerFactory, ioScheduler,
-                    ioOpCallbackProvider, linearizeCmpFactory, startIODeviceIndex);
+                    valueProviderFactories, rtreePolicyType, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider,
+                    linearizeCmpFactory, startIODeviceIndex);
         } catch (TreeIndexException e) {
             throw new HyracksDataException(e);
         }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
index b27e84f..7456c8c 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/dataflow/LSMRTreeWithAntiMatterTuplesDataflowHelperFactory.java
@@ -25,27 +25,30 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationSchedulerProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicyProvider;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
 import edu.uci.ics.hyracks.storage.am.rtree.frames.RTreePolicyType;
 
 public class LSMRTreeWithAntiMatterTuplesDataflowHelperFactory implements IIndexDataflowHelperFactory {
 
     private static final long serialVersionUID = 1L;
 
+    private final IVirtualBufferCacheProvider virtualBufferCacheProvider;
     private final IBinaryComparatorFactory[] btreeComparatorFactories;
     private final IPrimitiveValueProviderFactory[] valueProviderFactories;
     private final RTreePolicyType rtreePolicyType;
     private final ILSMMergePolicyProvider mergePolicyProvider;
-    private final ILSMOperationTrackerFactory opTrackerProvider;
+    private final ILSMOperationTrackerProvider opTrackerProvider;
     private final ILSMIOOperationSchedulerProvider ioSchedulerProvider;
     private final ILSMIOOperationCallbackProvider ioOpCallbackProvider;
     private final ILinearizeComparatorFactory linearizeCmpFactory;
 
     public LSMRTreeWithAntiMatterTuplesDataflowHelperFactory(IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType, IBinaryComparatorFactory[] btreeComparatorFactories,
-            ILSMMergePolicyProvider mergePolicyProvider, ILSMOperationTrackerFactory opTrackerProvider,
-            ILSMIOOperationSchedulerProvider ioSchedulerProvider, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
-            ILinearizeComparatorFactory linearizeCmpFactory) {
+            IVirtualBufferCacheProvider virtualBufferCacheProvider, ILSMMergePolicyProvider mergePolicyProvider,
+            ILSMOperationTrackerProvider opTrackerProvider, ILSMIOOperationSchedulerProvider ioSchedulerProvider,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizeCmpFactory) {
+        this.virtualBufferCacheProvider = virtualBufferCacheProvider;
         this.btreeComparatorFactories = btreeComparatorFactories;
         this.valueProviderFactories = valueProviderFactories;
         this.rtreePolicyType = rtreePolicyType;
@@ -59,7 +62,8 @@
     @Override
     public IndexDataflowHelper createIndexDataflowHelper(IIndexOperatorDescriptor opDesc, IHyracksTaskContext ctx,
             int partition) {
-        return new LSMRTreeWithAntiMatterTuplesDataflowHelper(opDesc, ctx, partition, btreeComparatorFactories,
+        return new LSMRTreeWithAntiMatterTuplesDataflowHelper(opDesc, ctx, partition,
+                virtualBufferCacheProvider.getVirtualBufferCache(ctx), btreeComparatorFactories,
                 valueProviderFactories, rtreePolicyType, mergePolicyProvider.getMergePolicy(ctx), opTrackerProvider,
                 ioSchedulerProvider.getIOScheduler(ctx), ioOpCallbackProvider, linearizeCmpFactory);
     }
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
index f62fab1..c8c1c77 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/AbstractLSMRTree.java
@@ -29,16 +29,15 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeAccessor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
 import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IndexException;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponentFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
@@ -47,8 +46,9 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractLSMIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BlockingIOOperationCallbackWrapper;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
@@ -57,6 +57,7 @@
 import edu.uci.ics.hyracks.storage.am.rtree.api.IRTreeLeafFrame;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree.RTreeAccessor;
+import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public abstract class AbstractLSMRTree extends AbstractLSMIndex implements ITreeIndex {
@@ -67,7 +68,8 @@
 
     // In-memory components.
     protected final LSMRTreeMutableComponent mutableComponent;
-    protected final IInMemoryBufferCache memBufferCache;
+    protected final IVirtualBufferCache virtualBufferCache;
+    protected final IVirtualFreePageManager virtualFreePageManager;
 
     protected TreeTupleSorter rTreeTupleSorter;
 
@@ -84,26 +86,27 @@
     protected final ITreeIndexFrameFactory rtreeLeafFrameFactory;
     protected final ITreeIndexFrameFactory btreeLeafFrameFactory;
 
-    public AbstractLSMRTree(IInMemoryBufferCache memBufferCache, IInMemoryFreePageManager memFreePageManager,
-            ITreeIndexFrameFactory rtreeInteriorFrameFactory, ITreeIndexFrameFactory rtreeLeafFrameFactory,
-            ITreeIndexFrameFactory btreeInteriorFrameFactory, ITreeIndexFrameFactory btreeLeafFrameFactory,
-            ILSMIndexFileManager fileManager, TreeIndexFactory<RTree> diskRTreeFactory,
-            ILSMComponentFactory componentFactory, IFileMapProvider diskFileMapProvider, int fieldCount,
-            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
-            ILinearizeComparatorFactory linearizer, int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray,
-            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+    public AbstractLSMRTree(IVirtualBufferCache virtualBufferCache, ITreeIndexFrameFactory rtreeInteriorFrameFactory,
+            ITreeIndexFrameFactory rtreeLeafFrameFactory, ITreeIndexFrameFactory btreeInteriorFrameFactory,
+            ITreeIndexFrameFactory btreeLeafFrameFactory, ILSMIndexFileManager fileManager,
+            TreeIndexFactory<RTree> diskRTreeFactory, ILSMComponentFactory componentFactory,
+            IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
+            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(memFreePageManager, diskRTreeFactory.getBufferCache(), fileManager, diskFileMapProvider,
-                bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
-        RTree memRTree = new RTree(memBufferCache, ((InMemoryBufferCache) memBufferCache).getFileMapProvider(),
-                memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, rtreeCmpFactories, fieldCount,
-                new FileReference(new File("memrtree")));
-        BTree memBTree = new BTree(memBufferCache, ((InMemoryBufferCache) memBufferCache).getFileMapProvider(),
-                memFreePageManager, btreeInteriorFrameFactory, btreeLeafFrameFactory, btreeCmpFactories, fieldCount,
-                new FileReference(new File("membtree")));
-        mutableComponent = new LSMRTreeMutableComponent(memRTree, memBTree, memFreePageManager);
-        this.memBufferCache = memBufferCache;
+        super(virtualBufferCache, diskRTreeFactory.getBufferCache(), fileManager, diskFileMapProvider,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
+        virtualFreePageManager = new VirtualFreePageManager(virtualBufferCache.getNumPages());
+        RTree memRTree = new RTree(virtualBufferCache, ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(),
+                virtualFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, rtreeCmpFactories,
+                fieldCount, new FileReference(new File(fileManager.getBaseDir() + "_virtual_r")));
+        BTree memBTree = new BTree(virtualBufferCache, ((IVirtualBufferCache) virtualBufferCache).getFileMapProvider(),
+                new VirtualFreePageManager(virtualBufferCache.getNumPages()), btreeInteriorFrameFactory,
+                btreeLeafFrameFactory, btreeCmpFactories, fieldCount, new FileReference(new File(
+                        fileManager.getBaseDir() + "_virtual_b")));
+        mutableComponent = new LSMRTreeMutableComponent(memRTree, memBTree, virtualBufferCache);
+        this.virtualBufferCache = virtualBufferCache;
         this.rtreeInteriorFrameFactory = rtreeInteriorFrameFactory;
         this.rtreeLeafFrameFactory = rtreeLeafFrameFactory;
         this.btreeInteriorFrameFactory = btreeInteriorFrameFactory;
@@ -134,7 +137,7 @@
             return;
         }
 
-        ((InMemoryBufferCache) mutableComponent.getRTree().getBufferCache()).open();
+        ((IVirtualBufferCache) mutableComponent.getRTree().getBufferCache()).open();
         mutableComponent.getRTree().create();
         mutableComponent.getBTree().create();
         mutableComponent.getRTree().activate();
@@ -164,7 +167,7 @@
         mutableComponent.getBTree().deactivate();
         mutableComponent.getRTree().destroy();
         mutableComponent.getBTree().destroy();
-        ((InMemoryBufferCache) mutableComponent.getRTree().getBufferCache()).close();
+        ((IVirtualBufferCache) mutableComponent.getRTree().getBufferCache()).close();
     }
 
     @Override
@@ -334,9 +337,9 @@
                 NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
 
         return new LSMRTreeOpContext(rtreeAccessor, (IRTreeLeafFrame) rtreeLeafFrameFactory.createFrame(),
-                (IRTreeInteriorFrame) rtreeInteriorFrameFactory.createFrame(), memFreePageManager
+                (IRTreeInteriorFrame) rtreeInteriorFrameFactory.createFrame(), virtualFreePageManager
                         .getMetaDataFrameFactory().createFrame(), 4, btreeAccessor, btreeLeafFrameFactory,
-                btreeInteriorFrameFactory, memFreePageManager.getMetaDataFrameFactory().createFrame(),
+                btreeInteriorFrameFactory, virtualFreePageManager.getMetaDataFrameFactory().createFrame(),
                 rtreeCmpFactories, btreeCmpFactories, modCallback, NoOpOperationCallback.INSTANCE);
     }
 
@@ -360,8 +363,8 @@
 
     @Override
     public long getMemoryAllocationSize() {
-        InMemoryBufferCache memBufferCache = (InMemoryBufferCache) mutableComponent.getRTree().getBufferCache();
-        return memBufferCache.getNumPages() * memBufferCache.getPageSize();
+        IBufferCache virtualBufferCache = mutableComponent.getRTree().getBufferCache();
+        return virtualBufferCache.getNumPages() * virtualBufferCache.getPageSize();
     }
 
     @Override
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
index 367b387..bdec9ce 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTree.java
@@ -30,7 +30,6 @@
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree.BTreeAccessor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
@@ -44,7 +43,6 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperation;
@@ -55,7 +53,8 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
@@ -67,22 +66,21 @@
 
 public class LSMRTree extends AbstractLSMRTree {
 
-    public LSMRTree(IInMemoryBufferCache memBufferCache, IInMemoryFreePageManager memFreePageManager,
-            ITreeIndexFrameFactory rtreeInteriorFrameFactory, ITreeIndexFrameFactory rtreeLeafFrameFactory,
-            ITreeIndexFrameFactory btreeInteriorFrameFactory, ITreeIndexFrameFactory btreeLeafFrameFactory,
-            ILSMIndexFileManager fileNameManager, TreeIndexFactory<RTree> diskRTreeFactory,
-            TreeIndexFactory<BTree> diskBTreeFactory, BloomFilterFactory bloomFilterFactory,
-            double bloomFilterFalsePositiveRate, IFileMapProvider diskFileMapProvider, int fieldCount,
-            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
-            ILinearizeComparatorFactory linearizer, int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
-                btreeInteriorFrameFactory, btreeLeafFrameFactory, fileNameManager, diskRTreeFactory,
-                new LSMRTreeComponentFactory(diskRTreeFactory, diskBTreeFactory, bloomFilterFactory),
-                diskFileMapProvider, fieldCount, rtreeCmpFactories, btreeCmpFactories, linearizer, comparatorFields,
-                linearizerArray, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory, ioScheduler,
-                ioOpCallbackProvider);
+    public LSMRTree(IVirtualBufferCache virtualBufferCache, ITreeIndexFrameFactory rtreeInteriorFrameFactory,
+            ITreeIndexFrameFactory rtreeLeafFrameFactory, ITreeIndexFrameFactory btreeInteriorFrameFactory,
+            ITreeIndexFrameFactory btreeLeafFrameFactory, ILSMIndexFileManager fileNameManager,
+            TreeIndexFactory<RTree> diskRTreeFactory, TreeIndexFactory<BTree> diskBTreeFactory,
+            BloomFilterFactory bloomFilterFactory, double bloomFilterFalsePositiveRate,
+            IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
+            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
+        super(virtualBufferCache, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory,
+                btreeLeafFrameFactory, fileNameManager, diskRTreeFactory, new LSMRTreeComponentFactory(
+                        diskRTreeFactory, diskBTreeFactory, bloomFilterFactory), diskFileMapProvider, fieldCount,
+                rtreeCmpFactories, btreeCmpFactories, linearizer, comparatorFields, linearizerArray,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
     }
 
     /**
@@ -246,13 +244,9 @@
 
         IBinaryComparatorFactory[] linearizerArray = { linearizer };
 
-        if (rTreeTupleSorter == null) {
-            rTreeTupleSorter = new TreeTupleSorter(flushingComponent.getRTree().getFileId(), linearizerArray,
-                    rtreeLeafFrameFactory.createFrame(), rtreeLeafFrameFactory.createFrame(), flushingComponent
-                            .getRTree().getBufferCache(), comparatorFields);
-        } else {
-            rTreeTupleSorter.reset();
-        }
+        rTreeTupleSorter = new TreeTupleSorter(flushingComponent.getRTree().getFileId(), linearizerArray,
+                rtreeLeafFrameFactory.createFrame(), rtreeLeafFrameFactory.createFrame(), flushingComponent.getRTree()
+                        .getBufferCache(), comparatorFields);
         // BulkLoad the tuples from the in-memory tree into the new disk
         // RTree.
 
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMutableComponent.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMutableComponent.java
index 2586d58..35fdde5 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMutableComponent.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeMutableComponent.java
@@ -17,7 +17,7 @@
 
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.AbstractMutableLSMComponent;
 import edu.uci.ics.hyracks.storage.am.rtree.impls.RTree;
 
@@ -25,12 +25,12 @@
 
     private final RTree rtree;
     private final BTree btree;
-    private final IInMemoryFreePageManager mfpm;
+    private final IVirtualBufferCache vbc;
 
-    public LSMRTreeMutableComponent(RTree rtree, BTree btree, IInMemoryFreePageManager mfpm) {
+    public LSMRTreeMutableComponent(RTree rtree, BTree btree, IVirtualBufferCache vbc) {
         this.rtree = rtree;
         this.btree = btree;
-        this.mfpm = mfpm;
+        this.vbc = vbc;
     }
 
     public RTree getRTree() {
@@ -43,15 +43,21 @@
 
     @Override
     protected boolean isFull() {
-        return mfpm.isFull();
+        return vbc.isFull();
     }
 
     @Override
     protected void reset() throws HyracksDataException {
         super.reset();
-        rtree.clear();
+        rtree.deactivate();
+        rtree.destroy();
+        rtree.create();
+        rtree.activate();
         if (btree != null) {
-            btree.clear();
+            btree.deactivate();
+            btree.destroy();
+            btree.create();
+            btree.activate();
         }
     }
 
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
index a3a8ca2..37c7a11 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/impls/LSMRTreeWithAntiMatterTuples.java
@@ -24,7 +24,6 @@
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTreeRangeSearchCursor;
 import edu.uci.ics.hyracks.storage.am.btree.impls.RangePredicate;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexBulkLoader;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.hyracks.storage.am.common.api.IModificationOperationCallback;
@@ -38,7 +37,6 @@
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.IndexOperation;
 import edu.uci.ics.hyracks.storage.am.common.ophelpers.MultiComparator;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponent;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMComponentFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMHarness;
@@ -50,7 +48,8 @@
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexOperationContext;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMComponentFileReferences;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.LSMTreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
@@ -68,21 +67,20 @@
     // because it should have a different tuple writer in it's leaf frames.
     private final ILSMComponentFactory bulkLoaComponentFactory;
 
-    public LSMRTreeWithAntiMatterTuples(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, ITreeIndexFrameFactory rtreeInteriorFrameFactory,
-            ITreeIndexFrameFactory rtreeLeafFrameFactory, ITreeIndexFrameFactory btreeInteriorFrameFactory,
-            ITreeIndexFrameFactory btreeLeafFrameFactory, ILSMIndexFileManager fileManager,
-            TreeIndexFactory<RTree> diskRTreeFactory, TreeIndexFactory<RTree> bulkLoadRTreeFactory,
-            IFileMapProvider diskFileMapProvider, int fieldCount, IBinaryComparatorFactory[] rtreeCmpFactories,
-            IBinaryComparatorFactory[] btreeCmpFactories, ILinearizeComparatorFactory linearizer,
-            int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+    public LSMRTreeWithAntiMatterTuples(IVirtualBufferCache virtualBufferCache,
+            ITreeIndexFrameFactory rtreeInteriorFrameFactory, ITreeIndexFrameFactory rtreeLeafFrameFactory,
+            ITreeIndexFrameFactory btreeInteriorFrameFactory, ITreeIndexFrameFactory btreeLeafFrameFactory,
+            ILSMIndexFileManager fileManager, TreeIndexFactory<RTree> diskRTreeFactory,
+            TreeIndexFactory<RTree> bulkLoadRTreeFactory, IFileMapProvider diskFileMapProvider, int fieldCount,
+            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
+            ILinearizeComparatorFactory linearizer, int[] comparatorFields, IBinaryComparatorFactory[] linearizerArray,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider) {
-        super(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
-                btreeInteriorFrameFactory, btreeLeafFrameFactory, fileManager, diskRTreeFactory,
-                new LSMRTreeWithAntiMatterTuplesComponentFactory(diskRTreeFactory), diskFileMapProvider, fieldCount,
-                rtreeCmpFactories, btreeCmpFactories, linearizer, comparatorFields, linearizerArray, 0, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        super(virtualBufferCache, rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory,
+                btreeLeafFrameFactory, fileManager, diskRTreeFactory, new LSMRTreeWithAntiMatterTuplesComponentFactory(
+                        diskRTreeFactory), diskFileMapProvider, fieldCount, rtreeCmpFactories, btreeCmpFactories,
+                linearizer, comparatorFields, linearizerArray, 0, mergePolicy, opTracker, ioScheduler,
+                ioOpCallbackProvider);
         bulkLoaComponentFactory = new LSMRTreeWithAntiMatterTuplesComponentFactory(bulkLoadRTreeFactory);
         this.bTreeTupleSorter = null;
     }
@@ -237,18 +235,13 @@
 
         // Since the LSM-RTree is used as a secondary assumption, the
         // primary key will be the last comparator in the BTree comparators
-        if (rTreeTupleSorter == null) {
-            rTreeTupleSorter = new TreeTupleSorter(flushingComponent.getRTree().getFileId(), linearizerArray,
-                    rtreeLeafFrameFactory.createFrame(), rtreeLeafFrameFactory.createFrame(), flushingComponent
-                            .getRTree().getBufferCache(), comparatorFields);
+        rTreeTupleSorter = new TreeTupleSorter(flushingComponent.getRTree().getFileId(), linearizerArray,
+                rtreeLeafFrameFactory.createFrame(), rtreeLeafFrameFactory.createFrame(), flushingComponent.getRTree()
+                        .getBufferCache(), comparatorFields);
 
-            bTreeTupleSorter = new TreeTupleSorter(flushingComponent.getBTree().getFileId(), linearizerArray,
-                    btreeLeafFrameFactory.createFrame(), btreeLeafFrameFactory.createFrame(), flushingComponent
-                            .getBTree().getBufferCache(), comparatorFields);
-        } else {
-            rTreeTupleSorter.reset();
-            bTreeTupleSorter.reset();
-        }
+        bTreeTupleSorter = new TreeTupleSorter(flushingComponent.getBTree().getFileId(), linearizerArray,
+                btreeLeafFrameFactory.createFrame(), btreeLeafFrameFactory.createFrame(), flushingComponent.getBTree()
+                        .getBufferCache(), comparatorFields);
         // BulkLoad the tuples from the in-memory tree into the new disk
         // RTree.
 
diff --git a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
index d299bfe..b80026e 100644
--- a/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
+++ b/hyracks/hyracks-storage-am-lsm-rtree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/utils/LSMRTreeUtils.java
@@ -26,19 +26,18 @@
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeNSMInteriorFrameFactory;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeNSMLeafFrameFactory;
 import edu.uci.ics.hyracks.storage.am.btree.impls.BTree;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.freepage.LinkedListFreePageManagerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexFileManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.BTreeFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.TreeIndexFactory;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTree;
@@ -60,13 +59,26 @@
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
 public class LSMRTreeUtils {
-    public static LSMRTree createLSMTree(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
-            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
-            IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+    public static LSMRTree createLSMTree(IVirtualBufferCache virtualBufferCache, IIOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
+            RTreePolicyType rtreePolicyType, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizeCmpFactory)
+            throws TreeIndexException {
+        return createLSMTree(virtualBufferCache, ioManager, file, diskBufferCache, diskFileMapProvider, typeTraits,
+                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
+                bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider,
+                linearizeCmpFactory, 0);
+    }
+
+    public static LSMRTree createLSMTree(IVirtualBufferCache virtualBufferCache, IIOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
+            IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
+            RTreePolicyType rtreePolicyType, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
+            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizeCmpFactory,
             int ioDeviceId) throws TreeIndexException {
         LSMTypeAwareTupleWriterFactory rtreeTupleWriterFactory = new LSMTypeAwareTupleWriterFactory(typeTraits, false);
@@ -103,23 +115,35 @@
 
         ILSMIndexFileManager fileNameManager = new LSMRTreeFileManager(ioManager, diskFileMapProvider, file,
                 diskRTreeFactory, diskBTreeFactory, ioDeviceId);
-        LSMRTree lsmTree = new LSMRTree(memBufferCache, memFreePageManager, rtreeInteriorFrameFactory,
-                rtreeLeafFrameFactory, btreeInteriorFrameFactory, btreeLeafFrameFactory, fileNameManager,
-                diskRTreeFactory, diskBTreeFactory, bloomFilterFactory, bloomFilterFalsePositiveRate,
-                diskFileMapProvider, typeTraits.length, rtreeCmpFactories, btreeCmpFactories, linearizeCmpFactory,
-                comparatorFields, linearizerArray, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+        LSMRTree lsmTree = new LSMRTree(virtualBufferCache, rtreeInteriorFrameFactory, rtreeLeafFrameFactory,
+                btreeInteriorFrameFactory, btreeLeafFrameFactory, fileNameManager, diskRTreeFactory, diskBTreeFactory,
+                bloomFilterFactory, bloomFilterFalsePositiveRate, diskFileMapProvider, typeTraits.length,
+                rtreeCmpFactories, btreeCmpFactories, linearizeCmpFactory, comparatorFields, linearizerArray,
+                mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
         return lsmTree;
     }
 
-    public static LSMRTreeWithAntiMatterTuples createLSMTreeWithAntiMatterTuples(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IIOManager ioManager, FileReference file,
+    public static LSMRTreeWithAntiMatterTuples createLSMTreeWithAntiMatterTuples(
+            IVirtualBufferCache virtualBufferCache, IIOManager ioManager, FileReference file,
             IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
             IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
             IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider,
-            ILinearizeComparatorFactory linearizerCmpFactory, int ioDeviceId) throws TreeIndexException {
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizerCmpFactory)
+            throws TreeIndexException {
+        return createLSMTreeWithAntiMatterTuples(virtualBufferCache, ioManager, file, diskBufferCache,
+                diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories, valueProviderFactories,
+                rtreePolicyType, mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider, linearizerCmpFactory, 0);
+    }
 
+    public static LSMRTreeWithAntiMatterTuples createLSMTreeWithAntiMatterTuples(
+            IVirtualBufferCache virtualBufferCache, IIOManager ioManager, FileReference file,
+            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ITypeTraits[] typeTraits,
+            IBinaryComparatorFactory[] rtreeCmpFactories, IBinaryComparatorFactory[] btreeCmpFactories,
+            IPrimitiveValueProviderFactory[] valueProviderFactories, RTreePolicyType rtreePolicyType,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider, ILinearizeComparatorFactory linearizerCmpFactory,
+            int ioDeviceId) throws TreeIndexException {
         LSMRTreeTupleWriterFactory rtreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, false);
         LSMRTreeTupleWriterFactory btreeTupleWriterFactory = new LSMRTreeTupleWriterFactory(typeTraits, true);
 
@@ -156,11 +180,11 @@
 
         ILSMIndexFileManager fileNameManager = new LSMRTreeWithAntiMatterTuplesFileManager(ioManager,
                 diskFileMapProvider, file, diskRTreeFactory, ioDeviceId);
-        LSMRTreeWithAntiMatterTuples lsmTree = new LSMRTreeWithAntiMatterTuples(memBufferCache, memFreePageManager,
+        LSMRTreeWithAntiMatterTuples lsmTree = new LSMRTreeWithAntiMatterTuples(virtualBufferCache,
                 rtreeInteriorFrameFactory, rtreeLeafFrameFactory, btreeInteriorFrameFactory, btreeLeafFrameFactory,
                 fileNameManager, diskRTreeFactory, bulkLoadRTreeFactory, diskFileMapProvider, typeTraits.length,
                 rtreeCmpFactories, btreeCmpFactories, linearizerCmpFactory, comparatorFields, linearizerArray,
-                mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider);
+                mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider);
         return lsmTree;
     }
 
diff --git a/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestVirtualBufferCacheProvider.java b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestVirtualBufferCacheProvider.java
new file mode 100644
index 0000000..1bf918b
--- /dev/null
+++ b/hyracks/hyracks-test-support/src/main/java/edu/uci/ics/hyracks/test/support/TestVirtualBufferCacheProvider.java
@@ -0,0 +1,25 @@
+package edu.uci.ics.hyracks.test.support;
+
+import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCacheProvider;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.VirtualBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
+
+public class TestVirtualBufferCacheProvider implements IVirtualBufferCacheProvider {
+
+    private static final long serialVersionUID = 1L;
+
+    private final int pageSize;
+    private final int numPages;
+
+    public TestVirtualBufferCacheProvider(int pageSize, int numPages) {
+        this.pageSize = pageSize;
+        this.numPages = numPages;
+    }
+
+    @Override
+    public IVirtualBufferCache getVirtualBufferCache(IHyracksTaskContext ctx) {
+        return new VirtualBufferCache(new HeapBufferAllocator(), pageSize, numPages);
+    }
+}
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
index a7eee57..56c7ecd 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeBulkLoadTest.java
@@ -51,11 +51,11 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(),harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
index a648ff6..a168114 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeDeleteTest.java
@@ -51,11 +51,11 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(),
-                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
index b5b0b76..081354e 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeExamplesTest.java
@@ -34,12 +34,11 @@
     @Override
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories,
             int[] bloomFilterKeyFields) throws TreeIndexException {
-        return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), typeTraits, cmpFactories, bloomFilterKeyFields,
-                harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
+                cmpFactories, bloomFilterKeyFields, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Before
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
index 875bbd4..56fc863 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeInsertTest.java
@@ -51,11 +51,11 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(),
-                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
index 43d38bc..eb92db1 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeLifecycleTest.java
@@ -42,12 +42,11 @@
     @Override
     public void setup() throws Exception {
         harness.setUp();
-        testCtx = LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, fieldSerdes.length,
-                harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        testCtx = LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, fieldSerdes.length, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
         index = testCtx.getIndex();
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
index 0ea2af2..85c2fa4 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
@@ -50,11 +50,11 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(),
-                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
index 901a31d..3e1278c 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeModificationOperationCallbackTest.java
@@ -42,12 +42,12 @@
 
     @Override
     protected void createIndexInstance() throws Exception {
-        index = LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), SerdeUtils.serdesToTypeTraits(keySerdes),
+        index = LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                SerdeUtils.serdesToTypeTraits(keySerdes),
                 SerdeUtils.serdesToComparatorFactories(keySerdes, keySerdes.length), bloomFilterKeyFields,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                NoOpOperationTrackerFactory.INSTANCE, harness.getIOScheduler(),
+                NoOpOperationTrackerFactory.INSTANCE.createOperationTracker(null), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
index ac8290e..1cad578 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMultiBulkLoadTest.java
@@ -52,11 +52,11 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(),
-                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
index 33e1641..b4027b6 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeSearchOperationCallbackTest.java
@@ -35,12 +35,12 @@
 
     @Override
     protected void createIndexInstance() throws Exception {
-        index = LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), SerdeUtils.serdesToTypeTraits(keySerdes),
+        index = LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                SerdeUtils.serdesToTypeTraits(keySerdes),
                 SerdeUtils.serdesToComparatorFactories(keySerdes, keySerdes.length), bloomFilterKeyFields,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                NoOpOperationTrackerFactory.INSTANCE, harness.getIOScheduler(),
+                NoOpOperationTrackerFactory.INSTANCE.createOperationTracker(null), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
index cc2db11..2f03f78 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeUpdateTest.java
@@ -51,11 +51,11 @@
     @Override
     protected OrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
             BTreeLeafFrameType leafType) throws Exception {
-        return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(),
-                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, numKeys, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
index d56ff5b..fdcb6f7 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/multithread/LSMBTreeMultiThreadTest.java
@@ -50,12 +50,11 @@
     @Override
     protected ITreeIndex createIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories,
             int[] bloomFilterKeyFields) throws TreeIndexException {
-        return LSMBTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), typeTraits, cmpFactories, bloomFilterKeyFields,
-                harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
-                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMBTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
+                cmpFactories, bloomFilterKeyFields, harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(), harness.getIOOperationCallbackProvider(),
+                harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/InMemoryBTreeRunner.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/InMemoryBTreeRunner.java
index 1b453b7..44300c1 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/InMemoryBTreeRunner.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/InMemoryBTreeRunner.java
@@ -30,18 +30,15 @@
 import edu.uci.ics.hyracks.storage.am.common.api.IFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
 import edu.uci.ics.hyracks.storage.am.common.datagen.TupleBatch;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.common.tuples.TypeAwareTupleWriterFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.VirtualBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICacheMemoryAllocator;
 import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
 
 public class InMemoryBTreeRunner extends Thread implements IExperimentRunner {
@@ -66,13 +63,11 @@
 
     protected void init(int pageSize, int numPages, ITypeTraits[] typeTraits, IBinaryComparatorFactory[] cmpFactories)
             throws HyracksDataException, BTreeException {
-        ICacheMemoryAllocator allocator = new HeapBufferAllocator();
-        bufferCache = new InMemoryBufferCache(allocator, pageSize, numPages, new TransientFileMapManager());
+        bufferCache = new VirtualBufferCache(new HeapBufferAllocator(), pageSize, numPages);
         TypeAwareTupleWriterFactory tupleWriterFactory = new TypeAwareTupleWriterFactory(typeTraits);
         ITreeIndexFrameFactory leafFrameFactory = new BTreeNSMLeafFrameFactory(tupleWriterFactory);
         ITreeIndexFrameFactory interiorFrameFactory = new BTreeNSMInteriorFrameFactory(tupleWriterFactory);
-        ITreeIndexMetaDataFrameFactory metaFrameFactory = new LIFOMetaDataFrameFactory();
-        IFreePageManager freePageManager = new InMemoryFreePageManager(bufferCache.getNumPages(), metaFrameFactory);
+        IFreePageManager freePageManager = new VirtualFreePageManager(bufferCache.getNumPages());
         btree = new BTree(bufferCache, new TransientFileMapManager(), freePageManager, interiorFrameFactory,
                 leafFrameFactory, cmpFactories, typeTraits.length, file);
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
index 7e54003..5c1ca0f 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/perf/LSMTreeRunner.java
@@ -26,27 +26,23 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.storage.am.btree.exceptions.BTreeException;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexAccessor;
 import edu.uci.ics.hyracks.storage.am.common.api.TreeIndexException;
 import edu.uci.ics.hyracks.storage.am.common.datagen.DataGenThread;
 import edu.uci.ics.hyracks.storage.am.common.datagen.TupleBatch;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeUtils;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SynchronousScheduler;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.VirtualBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
-import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
 import edu.uci.ics.hyracks.test.support.TestStorageManagerComponentHolder;
 import edu.uci.ics.hyracks.test.support.TestUtils;
 
@@ -92,15 +88,12 @@
         ioDeviceId = 0;
         IFileMapProvider fmp = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
 
-        IInMemoryBufferCache memBufferCache = new InMemoryBufferCache(new HeapBufferAllocator(), inMemPageSize,
-                inMemNumPages, new TransientFileMapManager());
-        IInMemoryFreePageManager memFreePageManager = new InMemoryFreePageManager(inMemNumPages,
-                new LIFOMetaDataFrameFactory());
+        IVirtualBufferCache virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), inMemPageSize,
+                inMemNumPages);
         this.ioScheduler = SynchronousScheduler.INSTANCE;
-        lsmtree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file, bufferCache, fmp,
-                typeTraits, cmpFactories, bloomFilterKeyFields, bloomFilterFalsePositiveRate, NoMergePolicy.INSTANCE,
-                ThreadCountingOperationTrackerFactory.INSTANCE, ioScheduler, NoOpIOOperationCallback.INSTANCE,
-                ioDeviceId);
+        lsmtree = LSMBTreeUtils.createLSMTree(virtualBufferCache, ioManager, file, bufferCache, fmp, typeTraits,
+                cmpFactories, bloomFilterKeyFields, bloomFilterFalsePositiveRate, NoMergePolicy.INSTANCE,
+                new ThreadCountingTracker(), ioScheduler, NoOpIOOperationCallback.INSTANCE, ioDeviceId);
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
index a830dc0..5195074 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestContext.java
@@ -25,14 +25,13 @@
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.storage.am.btree.OrderedIndexTestContext;
 import edu.uci.ics.hyracks.storage.am.common.CheckTuple;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
 import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
 
@@ -63,11 +62,10 @@
         upsertCheckTuple(checkTuple, checkTuples);
     }
 
-    public static LSMBTreeTestContext create(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
-            int numKeyFields, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+    public static LSMBTreeTestContext create(IVirtualBufferCache virtualBufferCache, IOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ISerializerDeserializer[] fieldSerdes, int numKeyFields, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider, int ioDeviceId) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] cmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes, numKeyFields);
@@ -75,10 +73,9 @@
         for (int i = 0; i < numKeyFields; ++i) {
             bloomFilterKeyFields[i] = i;
         }
-        LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file,
-                diskBufferCache, diskFileMapProvider, typeTraits, cmpFactories, bloomFilterKeyFields,
-                bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory, ioScheduler, ioOpCallbackProvider,
-                ioDeviceId);
+        LSMBTree lsmTree = LSMBTreeUtils.createLSMTree(virtualBufferCache, ioManager, file, diskBufferCache,
+                diskFileMapProvider, typeTraits, cmpFactories, bloomFilterKeyFields, bloomFilterFalsePositiveRate,
+                mergePolicy, opTracker, ioScheduler, ioOpCallbackProvider, ioDeviceId);
         LSMBTreeTestContext testCtx = new LSMBTreeTestContext(fieldSerdes, lsmTree);
         return testCtx;
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
index 066f57b..e84bced 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/util/LSMBTreeTestHarness.java
@@ -29,24 +29,20 @@
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SynchronousScheduler;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.VirtualBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
-import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
 import edu.uci.ics.hyracks.test.support.TestStorageManagerComponentHolder;
 import edu.uci.ics.hyracks.test.support.TestUtils;
 
@@ -69,12 +65,11 @@
     protected int ioDeviceId;
     protected IBufferCache diskBufferCache;
     protected IFileMapProvider diskFileMapProvider;
-    protected IInMemoryBufferCache memBufferCache;
-    protected IInMemoryFreePageManager memFreePageManager;
+    protected IVirtualBufferCache virtualBufferCache;
     protected IHyracksTaskContext ctx;
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMMergePolicy mergePolicy;
-    protected ILSMOperationTrackerFactory opTrackerFactory;
+    protected ILSMOperationTracker opTracker;
     protected ILSMIOOperationCallbackProvider ioOpCallbackProvider;
 
     protected final Random rnd = new Random();
@@ -93,7 +88,7 @@
         this.bloomFilterFalsePositiveRate = AccessMethodTestsConfig.LSM_BTREE_BLOOMFILTER_FALSE_POSITIVE_RATE;
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTrackerFactory = ThreadCountingOperationTrackerFactory.INSTANCE;
+        this.opTracker = new ThreadCountingTracker();
         this.ioOpCallbackProvider = NoOpIOOperationCallback.INSTANCE;
     }
 
@@ -108,7 +103,7 @@
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTrackerFactory = ThreadCountingOperationTrackerFactory.INSTANCE;
+        this.opTracker = new ThreadCountingTracker();
     }
 
     public void setUp() throws HyracksException {
@@ -118,9 +113,7 @@
         TestStorageManagerComponentHolder.init(diskPageSize, diskNumPages, diskMaxOpenFiles);
         diskBufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
         diskFileMapProvider = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
-        memBufferCache = new InMemoryBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages,
-                new TransientFileMapManager());
-        memFreePageManager = new InMemoryFreePageManager(memNumPages, new LIFOMetaDataFrameFactory());
+        virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages);
         ioManager = TestStorageManagerComponentHolder.getIOManager();
         ioDeviceId = 0;
         rnd.setSeed(RANDOM_SEED);
@@ -186,18 +179,14 @@
         return diskFileMapProvider;
     }
 
-    public IInMemoryBufferCache getMemBufferCache() {
-        return memBufferCache;
+    public IVirtualBufferCache getVirtualBufferCache() {
+        return virtualBufferCache;
     }
 
     public double getBoomFilterFalsePositiveRate() {
         return bloomFilterFalsePositiveRate;
     }
 
-    public IInMemoryFreePageManager getMemFreePageManager() {
-        return memFreePageManager;
-    }
-
     public IHyracksTaskContext getHyracksTastContext() {
         return ctx;
     }
@@ -214,8 +203,8 @@
         return ioScheduler;
     }
 
-    public ILSMOperationTrackerFactory getOperationTrackerFactory() {
-        return opTrackerFactory;
+    public ILSMOperationTracker getOperationTracker() {
+        return opTracker;
     }
 
     public ILSMMergePolicy getMergePolicy() {
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/InMemoryBufferCacheTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/InMemoryBufferCacheTest.java
deleted file mode 100644
index adba93d..0000000
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/InMemoryBufferCacheTest.java
+++ /dev/null
@@ -1,64 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package edu.uci.ics.hyracks.storage.am.lsm.common;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.fail;
-
-import java.util.HashSet;
-
-import org.junit.Test;
-
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
-import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
-import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
-import edu.uci.ics.hyracks.storage.common.file.TransientFileMapManager;
-
-public class InMemoryBufferCacheTest {
-    private static final int PAGE_SIZE = 256;
-    private static final int NUM_PAGES = 100;
-    private HashSet<ICachedPage> pinnedPages = new HashSet<ICachedPage>();
-
-    @Test
-    public void test01() throws Exception {
-        InMemoryBufferCache memBufferCache = new InMemoryBufferCache(new HeapBufferAllocator(), PAGE_SIZE, NUM_PAGES,
-                new TransientFileMapManager());
-        memBufferCache.open();
-        int dummyFileId = 0;
-        // Pin all pages, and make sure they return unique ICachedPages.
-        // We expect no overflow pages.
-        for (int i = 0; i < NUM_PAGES; i++) {
-            ICachedPage page = memBufferCache.pin(BufferedFileHandle.getDiskPageId(dummyFileId, i), false);
-            if (pinnedPages.contains(page)) {
-                fail("Id collision for ICachedPage, caused by id: " + i);
-            }
-            pinnedPages.add(page);
-            assertEquals(0, memBufferCache.getNumOverflowPages());
-        }
-        // Pin pages above capacity. We expect to be given new overflow pages.
-        // Going above capacity should be very rare, but nevertheless succeed.
-        for (int i = 0; i < 100; i++) {
-            ICachedPage page = memBufferCache.pin(BufferedFileHandle.getDiskPageId(dummyFileId, i + NUM_PAGES), false);
-            if (pinnedPages.contains(page)) {
-                fail("Id collision for ICachedPage, caused by overflow id: " + i);
-            }
-            pinnedPages.add(page);
-            assertEquals(i + 1, memBufferCache.getNumOverflowPages());
-        }
-        memBufferCache.close();
-    }
-}
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/InMemoryFreePageManagerTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/InMemoryFreePageManagerTest.java
deleted file mode 100644
index bd09a3f..0000000
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/InMemoryFreePageManagerTest.java
+++ /dev/null
@@ -1,65 +0,0 @@
-/*
- * Copyright 2009-2010 by The Regents of the University of California
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * you may obtain a copy of the License from
- * 
- *     http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package edu.uci.ics.hyracks.storage.am.lsm.common;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
-import org.junit.Test;
-
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
-import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndexMetaDataFrameFactory;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.InMemoryFreePageManager;
-
-public class InMemoryFreePageManagerTest {
-
-    private final int NUM_PAGES = 100;
-    
-    private void testInMemoryFreePageManager(InMemoryFreePageManager memFreePageManager) throws HyracksDataException {
-        // The first two pages are reserved for the BTree's metadata page and
-        // root page.
-        // The "actual" capacity is therefore numPages - 2.
-        int capacity = memFreePageManager.getCapacity();
-        assertEquals(capacity, NUM_PAGES - 2);
-        for (int i = 0; i < capacity; i++) {
-            int pageId = memFreePageManager.getFreePage(null);
-            // The free pages start from page 2;
-            assertEquals(i + 2, pageId);
-            assertFalse(memFreePageManager.isFull());
-        }
-        // Start asking for 100 pages above the capacity.
-        // Asking for pages above the capacity should be very rare, but
-        // nevertheless succeed.
-        // We expect isFull() to return true.
-        for (int i = 0; i < 100; i++) {
-            int pageId = memFreePageManager.getFreePage(null);
-            assertEquals(capacity + i + 2, pageId);
-            assertTrue(memFreePageManager.isFull());
-        }
-    }
-    
-    @Test
-    public void test01() throws HyracksDataException {
-        ITreeIndexMetaDataFrameFactory metaFrameFactory = new LIFOMetaDataFrameFactory();
-        InMemoryFreePageManager memFreePageManager = new InMemoryFreePageManager(NUM_PAGES, metaFrameFactory);
-        testInMemoryFreePageManager(memFreePageManager);
-        // We expect exactly the same behavior after a reset().
-        memFreePageManager.reset();
-        testInMemoryFreePageManager(memFreePageManager);
-    }
-}
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/VirtualBufferCacheTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/VirtualBufferCacheTest.java
new file mode 100644
index 0000000..38a001d
--- /dev/null
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/VirtualBufferCacheTest.java
@@ -0,0 +1,118 @@
+package edu.uci.ics.hyracks.storage.am.lsm.common;
+
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Random;
+import java.util.Set;
+
+import org.junit.Test;
+
+import edu.uci.ics.hyracks.api.io.FileReference;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.VirtualBufferCache;
+import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICacheMemoryAllocator;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPage;
+import edu.uci.ics.hyracks.storage.common.file.BufferedFileHandle;
+
+public class VirtualBufferCacheTest {
+    private static final long SEED = 123456789L;
+    private static final int NUM_OVERPIN = 128;
+    private static final int PAGE_SIZE = 256;
+    private static final int NUM_FILES = 10;
+    private static final int NUM_PAGES = 1000;
+
+    private final Random random;
+    private final FileState[] fileStates;
+
+    private VirtualBufferCache vbc;
+
+    public VirtualBufferCacheTest() {
+        fileStates = new FileState[NUM_FILES];
+        for (int i = 0; i < NUM_FILES; i++) {
+            fileStates[i] = new FileState();
+        }
+        random = new Random(SEED);
+        vbc = null;
+    }
+
+    private static class FileState {
+        private int fileId;
+        private FileReference fileRef;
+        private int pinCount;
+        private Set<ICachedPage> pinnedPages;
+
+        public FileState() {
+            fileId = -1;
+            fileRef = null;
+            pinCount = 0;
+            pinnedPages = new HashSet<ICachedPage>();
+        }
+    }
+
+    /**
+     * Pins NUM_PAGES randomly distributed across NUM_FILES and checks that each
+     * set of cached pages pinned on behalf of a file are disjoint from all other sets of
+     * cached pages pinned on behalf of other files.
+     * Additionally, the test perform the same test when pinning over soft cap (NUM_PAGES)
+     * of pages.
+     */
+    @Test
+    public void test01() throws Exception {
+        ICacheMemoryAllocator allocator = new HeapBufferAllocator();
+        vbc = new VirtualBufferCache(allocator, PAGE_SIZE, NUM_PAGES);
+        vbc.open();
+        createFiles();
+
+        kPins(NUM_PAGES);
+        assertTrue(pagesDisjointed());
+
+        kPins(NUM_OVERPIN);
+        assertTrue(pagesDisjointed());
+
+        deleteFiles();
+        vbc.close();
+    }
+
+    private boolean pagesDisjointed() {
+        boolean disjoint = true;
+        for (int i = 0; i < NUM_FILES; i++) {
+            FileState fi = fileStates[i];
+            for (int j = i + 1; j < NUM_FILES; j++) {
+                FileState fj = fileStates[j];
+                disjoint = disjoint && Collections.disjoint(fi.pinnedPages, fj.pinnedPages);
+            }
+        }
+        return disjoint;
+    }
+
+    private void createFiles() throws Exception {
+        for (int i = 0; i < NUM_FILES; i++) {
+            FileState f = fileStates[i];
+            String fName = String.format("f%d", i);
+            f.fileRef = new FileReference(new File(fName));
+            vbc.createFile(f.fileRef);
+            f.fileId = vbc.getFileMapProvider().lookupFileId(f.fileRef);
+        }
+    }
+
+    private void deleteFiles() throws Exception {
+        for (int i = 0; i < NUM_FILES; i++) {
+            vbc.deleteFile(fileStates[i].fileId, false);
+        }
+    }
+
+    private void kPins(int k) throws Exception {
+        int numPinned = 0;
+        while (numPinned < k) {
+            int fsIdx = random.nextInt(NUM_FILES);
+            FileState f = fileStates[fsIdx];
+            ICachedPage p = vbc.pin(BufferedFileHandle.getDiskPageId(f.fileId, f.pinCount), true);
+            f.pinnedPages.add(p);
+            ++f.pinCount;
+            ++numPinned;
+        }
+    }
+}
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/VirtualFreePageManagerTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/VirtualFreePageManagerTest.java
new file mode 100644
index 0000000..1dca8b3
--- /dev/null
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-common-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/common/VirtualFreePageManagerTest.java
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package edu.uci.ics.hyracks.storage.am.lsm.common;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
+
+public class VirtualFreePageManagerTest {
+
+    private final int NUM_PAGES = 100;
+
+    private void testInMemoryFreePageManager(VirtualFreePageManager virtualFreePageManager) throws HyracksDataException {
+        // The first two pages are reserved for the BTree's metadata page and
+        // root page.
+        // The "actual" capacity is therefore numPages - 2.
+        int capacity = virtualFreePageManager.getCapacity();
+        assertEquals(capacity, NUM_PAGES - 2);
+        for (int i = 0; i < capacity; i++) {
+            int pageId = virtualFreePageManager.getFreePage(null);
+            // The free pages start from page 2;
+            assertEquals(i + 2, pageId);
+        }
+        // Start asking for 100 pages above the capacity.
+        // Asking for pages above the capacity should be very rare, but
+        // nevertheless succeed.
+        // We expect isFull() to return true.
+        for (int i = 0; i < 100; i++) {
+            int pageId = virtualFreePageManager.getFreePage(null);
+            assertEquals(capacity + i + 2, pageId);
+        }
+    }
+
+    @Test
+    public void test01() throws HyracksDataException {
+        VirtualFreePageManager virtualFreePageManager = new VirtualFreePageManager(NUM_PAGES);
+        testInMemoryFreePageManager(virtualFreePageManager);
+        // We expect exactly the same behavior after a reset().
+        virtualFreePageManager.reset();
+        testInMemoryFreePageManager(virtualFreePageManager);
+    }
+}
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
index bf2d5e8..96c15a3 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/common/LSMInvertedIndexTestHarness.java
@@ -27,20 +27,19 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
+import edu.uci.ics.hyracks.storage.am.common.api.IVirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
+import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.VirtualFreePageManager;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SynchronousScheduler;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.VirtualBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -63,12 +62,12 @@
     protected int ioDeviceId;
     protected IBufferCache diskBufferCache;
     protected IFileMapProvider diskFileMapProvider;
-    protected IInMemoryBufferCache memBufferCache;
-    protected IInMemoryFreePageManager memFreePageManager;
+    protected IVirtualBufferCache virtualBufferCache;
+    protected IVirtualFreePageManager virtualFreePageManager;
     protected IHyracksTaskContext ctx;
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMMergePolicy mergePolicy;
-    protected ILSMOperationTrackerFactory opTrackerFactory;
+    protected ILSMOperationTracker opTracker;
     protected ILSMIOOperationCallbackProvider ioOpCallbackProvider;
 
     protected final Random rnd = new Random();
@@ -89,7 +88,7 @@
         this.bloomFilterFalsePositiveRate = AccessMethodTestsConfig.LSM_INVINDEX_BLOOMFILTER_FALSE_POSITIVE_RATE;
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTrackerFactory = ThreadCountingOperationTrackerFactory.INSTANCE;
+        this.opTracker = new ThreadCountingTracker();
         this.ioOpCallbackProvider = NoOpIOOperationCallback.INSTANCE;
     }
 
@@ -104,7 +103,7 @@
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTrackerFactory = ThreadCountingOperationTrackerFactory.INSTANCE;
+        this.opTracker = new ThreadCountingTracker();
     }
 
     public void setUp() throws HyracksException {
@@ -113,9 +112,9 @@
         TestStorageManagerComponentHolder.init(diskPageSize, diskNumPages, diskMaxOpenFiles);
         diskBufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
         diskFileMapProvider = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
-        memBufferCache = new DualIndexInMemoryBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages);
-        memBufferCache.open();
-        memFreePageManager = new DualIndexInMemoryFreePageManager(memNumPages, new LIFOMetaDataFrameFactory());
+        virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages);
+        virtualBufferCache.open();
+        virtualFreePageManager = new VirtualFreePageManager(memNumPages);
         ioManager = TestStorageManagerComponentHolder.getIOManager();
         ioDeviceId = 0;
         rnd.setSeed(RANDOM_SEED);
@@ -140,7 +139,7 @@
             }
             dir.delete();
         }
-        memBufferCache.close();
+        virtualBufferCache.close();
     }
 
     public FileReference getInvListsFileRef() {
@@ -187,16 +186,16 @@
         return diskFileMapProvider;
     }
 
-    public IInMemoryBufferCache getMemBufferCache() {
-        return memBufferCache;
+    public IVirtualBufferCache getVirtualBufferCache() {
+        return virtualBufferCache;
     }
 
     public double getBoomFilterFalsePositiveRate() {
         return bloomFilterFalsePositiveRate;
     }
 
-    public IInMemoryFreePageManager getMemFreePageManager() {
-        return memFreePageManager;
+    public IVirtualFreePageManager getVirtualFreePageManager() {
+        return virtualFreePageManager;
     }
 
     public IHyracksTaskContext getHyracksTastContext() {
@@ -215,8 +214,8 @@
         return ioScheduler;
     }
 
-    public ILSMOperationTrackerFactory getOperationTrackerFactory() {
-        return opTrackerFactory;
+    public ILSMOperationTracker getOperationTracker() {
+        return opTracker;
     }
 
     public ILSMMergePolicy getMergePolicy() {
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
index f955fc9..f28d3b6 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-invertedindex-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/invertedindex/util/LSMInvertedIndexTestContext.java
@@ -18,6 +18,7 @@
 import java.io.ByteArrayInputStream;
 import java.io.DataInput;
 import java.io.DataInputStream;
+import java.io.File;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
@@ -27,6 +28,7 @@
 import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
 import edu.uci.ics.hyracks.api.dataflow.value.ITypeTraits;
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
 import edu.uci.ics.hyracks.dataflow.common.util.TupleUtils;
@@ -118,15 +120,16 @@
         IInvertedIndex invIndex;
         switch (invIndexType) {
             case INMEMORY: {
-                invIndex = InvertedIndexUtils.createInMemoryBTreeInvertedindex(harness.getMemBufferCache(),
-                        harness.getMemFreePageManager(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
-                        tokenCmpFactories, tokenizerFactory);
+                invIndex = InvertedIndexUtils.createInMemoryBTreeInvertedindex(harness.getVirtualBufferCache(),
+                        harness.getVirtualFreePageManager(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
+                        tokenCmpFactories, tokenizerFactory, new FileReference(new File(harness.getOnDiskDir())));
                 break;
             }
             case PARTITIONED_INMEMORY: {
-                invIndex = InvertedIndexUtils.createPartitionedInMemoryBTreeInvertedindex(harness.getMemBufferCache(),
-                        harness.getMemFreePageManager(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
-                        tokenCmpFactories, tokenizerFactory);
+                invIndex = InvertedIndexUtils.createPartitionedInMemoryBTreeInvertedindex(harness
+                        .getVirtualBufferCache(), harness.getVirtualFreePageManager(), invListTypeTraits,
+                        invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory, new FileReference(
+                                new File(harness.getOnDiskDir())));
                 break;
             }
             case ONDISK: {
@@ -142,22 +145,20 @@
                 break;
             }
             case LSM: {
-                invIndex = InvertedIndexUtils.createLSMInvertedIndex(harness.getMemBufferCache(),
-                        harness.getMemFreePageManager(), harness.getDiskFileMapProvider(), invListTypeTraits,
-                        invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory,
-                        harness.getDiskBufferCache(), harness.getIOManager(), harness.getOnDiskDir(),
-                        harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                        harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                invIndex = InvertedIndexUtils.createLSMInvertedIndex(harness.getVirtualBufferCache(),
+                        harness.getDiskFileMapProvider(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
+                        tokenCmpFactories, tokenizerFactory, harness.getDiskBufferCache(), harness.getIOManager(),
+                        harness.getOnDiskDir(), harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                        harness.getOperationTracker(), harness.getIOScheduler(),
                         harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
                 break;
             }
             case PARTITIONED_LSM: {
-                invIndex = InvertedIndexUtils.createPartitionedLSMInvertedIndex(harness.getMemBufferCache(),
-                        harness.getMemFreePageManager(), harness.getDiskFileMapProvider(), invListTypeTraits,
-                        invListCmpFactories, tokenTypeTraits, tokenCmpFactories, tokenizerFactory,
-                        harness.getDiskBufferCache(), harness.getIOManager(), harness.getOnDiskDir(),
-                        harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                        harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                invIndex = InvertedIndexUtils.createPartitionedLSMInvertedIndex(harness.getVirtualBufferCache(),
+                        harness.getDiskFileMapProvider(), invListTypeTraits, invListCmpFactories, tokenTypeTraits,
+                        tokenCmpFactories, tokenizerFactory, harness.getDiskBufferCache(), harness.getIOManager(),
+                        harness.getOnDiskDir(), harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                        harness.getOperationTracker(), harness.getIOScheduler(),
                         harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
                 break;
             }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
index edd24b4..f579738 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeBulkLoadTest.java
@@ -54,11 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
index 360c02c..315b0ea 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeDeleteTest.java
@@ -54,11 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
index 0c68fa6..ecd7e02 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeExamplesTest.java
@@ -37,11 +37,11 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(),
-                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+        return LSMRTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
+                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
+                harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length), harness.getIODeviceId());
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
index f39b139..e790cb2 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeInsertTest.java
@@ -54,11 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
index 8bee460..ff14ab6 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeLifecycleTest.java
@@ -52,11 +52,11 @@
     @Override
     public void setup() throws Exception {
         harness.setUp();
-        testCtx = LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, RTreePolicyType.RTREE,
+        testCtx = LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, RTreePolicyType.RTREE,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
         index = testCtx.getIndex();
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
index 5d7d31b..1702e99 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMergeTest.java
@@ -53,11 +53,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java
index 8ef0a9f..81db7bc 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeMultiBulkLoadTest.java
@@ -54,11 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
+        return LSMRTreeTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType,
                 harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
index f778aa9..efff30c 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesBulkLoadTest.java
@@ -54,12 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getMergePolicy(), harness.getOperationTrackerFactory(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
-
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
index 44d3d1b..485b958f 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesDeleteTest.java
@@ -54,12 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getMergePolicy(), harness.getOperationTrackerFactory(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
-
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
index 8b12224..b6b5195 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesExamplesTest.java
@@ -37,11 +37,10 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
-                btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
+                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
+                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length), harness.getIODeviceId());
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
index 96ef868..fecb1c6 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesInsertTest.java
@@ -54,12 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getMergePolicy(), harness.getOperationTrackerFactory(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
-
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
index 012559d..9ce0d25 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesLifecycleTest.java
@@ -52,11 +52,11 @@
     @Override
     public void setup() throws Exception {
         harness.setUp();
-        testCtx = LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, RTreePolicyType.RTREE, harness.getMergePolicy(), harness.getOperationTrackerFactory(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        testCtx = LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(),
+                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
+                harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories, numKeys, RTreePolicyType.RTREE,
+                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
         index = testCtx.getIndex();
     }
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
index 1c67cd0..bb15e6d 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMergeTest.java
@@ -53,11 +53,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getMergePolicy(), harness.getOperationTrackerFactory(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java
index fe61afd..d93129d 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/LSMRTreeWithAntiMatterTuplesMultiBulkLoadTest.java
@@ -54,12 +54,11 @@
     protected AbstractRTreeTestContext createTestContext(ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeys, RTreePolicyType rtreePolicyType)
             throws Exception {
-        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes, valueProviderFactories,
-                numKeys, rtreePolicyType, harness.getMergePolicy(), harness.getOperationTrackerFactory(),
-                harness.getIOScheduler(), harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
-
+        return LSMRTreeWithAntiMatterTuplesTestContext.create(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(),
+                fieldSerdes, valueProviderFactories, numKeys, rtreePolicyType, harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
+                harness.getIOOperationCallbackProvider(), harness.getIODeviceId());
     }
 
     @Override
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
index 1d2271c..11071ea 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeMultiThreadTest.java
@@ -57,11 +57,11 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTree(harness.getMemBufferCache(), harness.getMemFreePageManager(),
-                harness.getIOManager(), harness.getFileReference(), harness.getDiskBufferCache(),
-                harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, harness.getBoomFilterFalsePositiveRate(),
-                harness.getMergePolicy(), harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+        return LSMRTreeUtils.createLSMTree(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
+                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
+                harness.getBoomFilterFalsePositiveRate(), harness.getMergePolicy(),
+                harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length), harness.getIODeviceId());
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
index aa5023d..4fffdfd 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/multithread/LSMRTreeWithAntiMatterTuplesMultiThreadTest.java
@@ -57,11 +57,10 @@
     protected ITreeIndex createTreeIndex(ITypeTraits[] typeTraits, IBinaryComparatorFactory[] rtreeCmpFactories,
             IBinaryComparatorFactory[] btreeCmpFactories, IPrimitiveValueProviderFactory[] valueProviderFactories,
             RTreePolicyType rtreePolicyType) throws TreeIndexException {
-        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getMemBufferCache(),
-                harness.getMemFreePageManager(), harness.getIOManager(), harness.getFileReference(),
-                harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits, rtreeCmpFactories,
-                btreeCmpFactories, valueProviderFactories, rtreePolicyType, harness.getMergePolicy(),
-                harness.getOperationTrackerFactory(), harness.getIOScheduler(),
+        return LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(harness.getVirtualBufferCache(), harness.getIOManager(),
+                harness.getFileReference(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), typeTraits,
+                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType,
+                harness.getMergePolicy(), harness.getOperationTracker(), harness.getIOScheduler(),
                 harness.getIOOperationCallbackProvider(),
                 LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length), harness.getIODeviceId());
 
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
index fb9fb23..df95773 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestContext.java
@@ -23,14 +23,13 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTree;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeTestContext;
@@ -67,23 +66,22 @@
         return lsmTree.getComparatorFactories();
     }
 
-    public static LSMRTreeTestContext create(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
-            IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
-            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTrackerFactory opTrackerFactory, ILSMIOOperationScheduler ioScheduler,
+    public static LSMRTreeTestContext create(IVirtualBufferCache virtualBufferCache, IOManager ioManager,
+            FileReference file, IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider,
+            ISerializerDeserializer[] fieldSerdes, IPrimitiveValueProviderFactory[] valueProviderFactories,
+            int numKeyFields, RTreePolicyType rtreePolicyType, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
             ILSMIOOperationCallbackProvider ioOpCallbackProvider, int ioDeviceId) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
         IBinaryComparatorFactory[] btreeCmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes,
                 fieldSerdes.length);
-        LSMRTree lsmTree = LSMRTreeUtils.createLSMTree(memBufferCache, memFreePageManager, ioManager, file,
-                diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories,
-                valueProviderFactories, rtreePolicyType, bloomFilterFalsePositiveRate, mergePolicy, opTrackerFactory,
-                ioScheduler, ioOpCallbackProvider,
-                LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length), ioDeviceId);
+        LSMRTree lsmTree = LSMRTreeUtils.createLSMTree(virtualBufferCache, ioManager, file, diskBufferCache,
+                diskFileMapProvider, typeTraits, rtreeCmpFactories, btreeCmpFactories, valueProviderFactories,
+                rtreePolicyType, bloomFilterFalsePositiveRate, mergePolicy, opTracker, ioScheduler,
+                ioOpCallbackProvider, LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length),
+                ioDeviceId);
         LSMRTreeTestContext testCtx = new LSMRTreeTestContext(fieldSerdes, lsmTree);
         return testCtx;
     }
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
index 4c2e83b..5f0072e 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeTestHarness.java
@@ -28,20 +28,17 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IODeviceHandle;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
-import edu.uci.ics.hyracks.storage.am.common.frames.LIFOMetaDataFrameFactory;
 import edu.uci.ics.hyracks.storage.am.config.AccessMethodTestsConfig;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryBufferCache;
-import edu.uci.ics.hyracks.storage.am.lsm.common.freepage.DualIndexInMemoryFreePageManager;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoMergePolicy;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.NoOpIOOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.impls.SynchronousScheduler;
-import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.ThreadCountingTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.impls.VirtualBufferCache;
 import edu.uci.ics.hyracks.storage.common.buffercache.HeapBufferAllocator;
 import edu.uci.ics.hyracks.storage.common.buffercache.IBufferCache;
 import edu.uci.ics.hyracks.storage.common.file.IFileMapProvider;
@@ -65,13 +62,12 @@
     protected int ioDeviceId;
     protected IBufferCache diskBufferCache;
     protected IFileMapProvider diskFileMapProvider;
-    protected IInMemoryBufferCache memBufferCache;
-    protected IInMemoryFreePageManager memFreePageManager;
+    protected IVirtualBufferCache virtualBufferCache;
     protected IHyracksTaskContext ctx;
     protected ILSMIOOperationScheduler ioScheduler;
     protected ILSMIOOperationCallbackProvider ioOpCallbackProvider;
     protected ILSMMergePolicy mergePolicy;
-    protected ILSMOperationTrackerFactory opTrackerFactory;
+    protected ILSMOperationTracker opTracker;
 
     protected final Random rnd = new Random();
     protected final static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("ddMMyy-hhmmssSS");
@@ -89,7 +85,7 @@
         this.hyracksFrameSize = AccessMethodTestsConfig.LSM_RTREE_HYRACKS_FRAME_SIZE;
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTrackerFactory = ThreadCountingOperationTrackerFactory.INSTANCE;
+        this.opTracker = new ThreadCountingTracker();
         this.ioOpCallbackProvider = NoOpIOOperationCallback.INSTANCE;
     }
 
@@ -104,7 +100,7 @@
         this.hyracksFrameSize = hyracksFrameSize;
         this.ioScheduler = SynchronousScheduler.INSTANCE;
         this.mergePolicy = NoMergePolicy.INSTANCE;
-        this.opTrackerFactory = ThreadCountingOperationTrackerFactory.INSTANCE;
+        this.opTracker = new ThreadCountingTracker();
     }
 
     public void setUp() throws HyracksException {
@@ -114,8 +110,7 @@
         TestStorageManagerComponentHolder.init(diskPageSize, diskNumPages, diskMaxOpenFiles);
         diskBufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
         diskFileMapProvider = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
-        memBufferCache = new DualIndexInMemoryBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages);
-        memFreePageManager = new DualIndexInMemoryFreePageManager(memNumPages, new LIFOMetaDataFrameFactory());
+        virtualBufferCache = new VirtualBufferCache(new HeapBufferAllocator(), memPageSize, memNumPages);
         ioManager = TestStorageManagerComponentHolder.getIOManager();
         ioDeviceId = 0;
         rnd.setSeed(RANDOM_SEED);
@@ -181,18 +176,14 @@
         return diskFileMapProvider;
     }
 
-    public IInMemoryBufferCache getMemBufferCache() {
-        return memBufferCache;
+    public IVirtualBufferCache getVirtualBufferCache() {
+        return virtualBufferCache;
     }
 
     public double getBoomFilterFalsePositiveRate() {
         return bloomFilterFalsePositiveRate;
     }
 
-    public IInMemoryFreePageManager getMemFreePageManager() {
-        return memFreePageManager;
-    }
-
     public IHyracksTaskContext getHyracksTastContext() {
         return ctx;
     }
@@ -213,8 +204,8 @@
         return ioScheduler;
     }
 
-    public ILSMOperationTrackerFactory getOperationTrackerFactory() {
-        return opTrackerFactory;
+    public ILSMOperationTracker getOperationTracker() {
+        return opTracker;
     }
 
     public ILSMMergePolicy getMergePolicy() {
diff --git a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
index 48cc481..dbb4e28 100644
--- a/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
+++ b/hyracks/hyracks-tests/hyracks-storage-am-lsm-rtree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/rtree/util/LSMRTreeWithAntiMatterTuplesTestContext.java
@@ -23,14 +23,13 @@
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.control.nc.io.IOManager;
 import edu.uci.ics.hyracks.dataflow.common.util.SerdeUtils;
-import edu.uci.ics.hyracks.storage.am.common.api.IInMemoryFreePageManager;
 import edu.uci.ics.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
 import edu.uci.ics.hyracks.storage.am.common.api.ITreeIndex;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.IInMemoryBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationCallbackProvider;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIOOperationScheduler;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMMergePolicy;
-import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTrackerFactory;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMOperationTracker;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.IVirtualBufferCache;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.impls.LSMRTreeWithAntiMatterTuples;
 import edu.uci.ics.hyracks.storage.am.lsm.rtree.utils.LSMRTreeUtils;
 import edu.uci.ics.hyracks.storage.am.rtree.AbstractRTreeTestContext;
@@ -67,23 +66,22 @@
         return lsmTree.getComparatorFactories();
     }
 
-    public static LSMRTreeWithAntiMatterTuplesTestContext create(IInMemoryBufferCache memBufferCache,
-            IInMemoryFreePageManager memFreePageManager, IOManager ioManager, FileReference file,
-            IBufferCache diskBufferCache, IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
+    public static LSMRTreeWithAntiMatterTuplesTestContext create(IVirtualBufferCache virtualBufferCache,
+            IOManager ioManager, FileReference file, IBufferCache diskBufferCache,
+            IFileMapProvider diskFileMapProvider, ISerializerDeserializer[] fieldSerdes,
             IPrimitiveValueProviderFactory[] valueProviderFactories, int numKeyFields, RTreePolicyType rtreePolicyType,
-            ILSMMergePolicy mergePolicy, ILSMOperationTrackerFactory opTrackerFactory,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallbackProvider ioOpCallbackProvider, int ioDeviceId)
-            throws Exception {
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallbackProvider ioOpCallbackProvider, int ioDeviceId) throws Exception {
         ITypeTraits[] typeTraits = SerdeUtils.serdesToTypeTraits(fieldSerdes);
         IBinaryComparatorFactory[] rtreeCmpFactories = SerdeUtils
                 .serdesToComparatorFactories(fieldSerdes, numKeyFields);
         IBinaryComparatorFactory[] btreeCmpFactories = SerdeUtils.serdesToComparatorFactories(fieldSerdes,
                 fieldSerdes.length);
-        LSMRTreeWithAntiMatterTuples lsmTree = LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(memBufferCache,
-                memFreePageManager, ioManager, file, diskBufferCache, diskFileMapProvider, typeTraits,
-                rtreeCmpFactories, btreeCmpFactories, valueProviderFactories, rtreePolicyType, mergePolicy,
-                opTrackerFactory, ioScheduler, ioOpCallbackProvider,
-                LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length), ioDeviceId);
+        LSMRTreeWithAntiMatterTuples lsmTree = LSMRTreeUtils.createLSMTreeWithAntiMatterTuples(virtualBufferCache,
+                ioManager, file, diskBufferCache, diskFileMapProvider, typeTraits, rtreeCmpFactories,
+                btreeCmpFactories, valueProviderFactories, rtreePolicyType, mergePolicy, opTracker, ioScheduler,
+                ioOpCallbackProvider, LSMRTreeUtils.proposeBestLinearizer(typeTraits, rtreeCmpFactories.length),
+                ioDeviceId);
         LSMRTreeWithAntiMatterTuplesTestContext testCtx = new LSMRTreeWithAntiMatterTuplesTestContext(fieldSerdes,
                 lsmTree);
         return testCtx;
diff --git a/hyracks/hyracks-tests/hyracks-storage-common-test/src/test/java/edu/uci/ics/hyracks/storage/common/BufferCacheRegressionTests.java b/hyracks/hyracks-tests/hyracks-storage-common-test/src/test/java/edu/uci/ics/hyracks/storage/common/BufferCacheRegressionTest.java
similarity index 71%
rename from hyracks/hyracks-tests/hyracks-storage-common-test/src/test/java/edu/uci/ics/hyracks/storage/common/BufferCacheRegressionTests.java
rename to hyracks/hyracks-tests/hyracks-storage-common-test/src/test/java/edu/uci/ics/hyracks/storage/common/BufferCacheRegressionTest.java
index a649aa7..cc73e34 100644
--- a/hyracks/hyracks-tests/hyracks-storage-common-test/src/test/java/edu/uci/ics/hyracks/storage/common/BufferCacheRegressionTests.java
+++ b/hyracks/hyracks-tests/hyracks-storage-common-test/src/test/java/edu/uci/ics/hyracks/storage/common/BufferCacheRegressionTest.java
@@ -9,7 +9,6 @@
 import org.junit.Test;
 
 import edu.uci.ics.hyracks.api.context.IHyracksTaskContext;
-import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.api.io.FileReference;
 import edu.uci.ics.hyracks.api.io.IFileHandle;
 import edu.uci.ics.hyracks.api.io.IIOManager;
@@ -22,7 +21,7 @@
 import edu.uci.ics.hyracks.test.support.TestStorageManagerComponentHolder;
 import edu.uci.ics.hyracks.test.support.TestUtils;
 
-public class BufferCacheRegressionTests {
+public class BufferCacheRegressionTest {
     protected static final String tmpDir = System.getProperty("java.io.tmpdir");
     protected static final String sep = System.getProperty("file.separator");
 
@@ -121,51 +120,4 @@
         }
         bufferCache.close();
     }
-
-    // Tests the behavior of the BufferCache when more than all pages are
-    // pinned. We expect an exception.
-    @Test
-    public void testPinningAllPages() throws HyracksDataException {
-        int numPages = 10;
-        TestStorageManagerComponentHolder.init(PAGE_SIZE, numPages, 1);
-
-        IBufferCache bufferCache = TestStorageManagerComponentHolder.getBufferCache(ctx);
-        IFileMapProvider fmp = TestStorageManagerComponentHolder.getFileMapProvider(ctx);
-
-        FileReference firstFileRef = new FileReference(new File(fileName));
-        bufferCache.createFile(firstFileRef);
-        int fileId = fmp.lookupFileId(firstFileRef);
-        bufferCache.openFile(fileId);
-
-        // Pin all pages.
-        ICachedPage[] pages = new ICachedPage[numPages];
-        for (int i = 0; i < numPages; ++i) {
-            pages[i] = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, i), true);
-        }
-
-        // Try to pin another page. We expect a HyracksDataException.
-        ICachedPage errorPage = null;
-        try {
-            errorPage = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, numPages), true);
-        } catch (HyracksDataException e) {
-            // This is the expected outcome.
-            // The BufferCache should still be able to function properly.
-            // Try unpinning all pages.
-            for (int i = 0; i < numPages; ++i) {
-                bufferCache.unpin(pages[i]);
-            }
-            // Now try pinning the page that failed above again.
-            errorPage = bufferCache.pin(BufferedFileHandle.getDiskPageId(fileId, numPages), true);
-            // Unpin it.
-            bufferCache.unpin(errorPage);
-            // Cleanup.
-            bufferCache.closeFile(fileId);
-            bufferCache.close();
-            return;
-        } catch (Exception e) {
-            fail("Expected a HyracksDataException when pinning more pages than available but got another exception: "
-                    + e.getMessage());
-        }
-        fail("Expected a HyracksDataException when pinning more pages than available.");
-    }
 }