diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java
index 85f90e4..d7ff15d 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java
@@ -31,6 +31,9 @@
     private static final String STORAGE_MEMORYCOMPONENT_NUMPAGES_KEY = "storage.memorycomponent.numpages";
     private static final int STORAGE_MEMORYCOMPONENT_NUMPAGES_DEFAULT = 1024; // ... so 32MB components
 
+    private static final String STORAGE_MEMORYCOMPONENT_NUMCOMPONENTS_KEY = "storage.memorycomponent.numcomponents";
+    private static final int STORAGE_MEMORYCOMPONENT_NUMCOMPONENTS_DEFAULT = 2; // 2 components
+
     private static final String STORAGE_MEMORYCOMPONENT_GLOBALBUDGET_KEY = "storage.memorycomponent.globalbudget";
     private static final long STORAGE_MEMORYCOMPONENT_GLOBALBUDGET_DEFAULT = 536870912; // 512MB
 
@@ -53,7 +56,7 @@
         return accessor.getProperty(STORAGE_BUFFERCACHE_SIZE_KEY, STORAGE_BUFFERCACHE_SIZE_DEFAULT,
                 PropertyInterpreters.getLongPropertyInterpreter());
     }
-    
+
     public int getBufferCacheNumPages() {
         return (int) (getBufferCacheSize() / getBufferCachePageSize());
     }
@@ -73,6 +76,11 @@
                 PropertyInterpreters.getIntegerPropertyInterpreter());
     }
 
+    public int getMemoryComponentsNum() {
+        return accessor.getProperty(STORAGE_MEMORYCOMPONENT_NUMCOMPONENTS_KEY,
+                STORAGE_MEMORYCOMPONENT_NUMCOMPONENTS_DEFAULT, PropertyInterpreters.getIntegerPropertyInterpreter());
+    }
+
     public long getMemoryComponentGlobalBudget() {
         return accessor.getProperty(STORAGE_MEMORYCOMPONENT_GLOBALBUDGET_KEY,
                 STORAGE_MEMORYCOMPONENT_GLOBALBUDGET_DEFAULT, PropertyInterpreters.getLongPropertyInterpreter());
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/DatasetLifecycleManager.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/DatasetLifecycleManager.java
index ded7237..eea3d99 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/DatasetLifecycleManager.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/context/DatasetLifecycleManager.java
@@ -31,7 +31,9 @@
 import edu.uci.ics.hyracks.api.lifecycle.ILifeCycleComponent;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndex;
 import edu.uci.ics.hyracks.storage.am.common.api.IIndexLifecycleManager;
+import edu.uci.ics.hyracks.storage.am.common.impls.NoOpOperationCallback;
 import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndex;
+import edu.uci.ics.hyracks.storage.am.lsm.common.api.ILSMIndexAccessor;
 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.MultitenantVirtualBufferCache;
@@ -48,7 +50,6 @@
     private final ILocalResourceRepository resourceRepository;
     private final long capacity;
     private long used;
-    private final static int NUM_MUTABLE_BUFFERS = 2;
 
     public DatasetLifecycleManager(AsterixStorageProperties storageProperties,
             ILocalResourceRepository resourceRepository) {
@@ -96,48 +97,61 @@
     }
 
     @Override
-    public void unregister(long resourceID) throws HyracksDataException {
-        int did;
-        PrimaryIndexOperationTracker opTracker;
-        DatasetInfo dsInfo;
-        IndexInfo iInfo;
-        synchronized (this) {
-            did = getDIDfromRID(resourceID);
-            dsInfo = datasetInfos.get(did);
-            iInfo = dsInfo.indexes.get(resourceID);
+    public synchronized void unregister(long resourceID) throws HyracksDataException {
+        int did = getDIDfromRID(resourceID);
+        DatasetInfo dsInfo = datasetInfos.get(did);
+        IndexInfo iInfo = dsInfo.indexes.get(resourceID);
 
-            if (dsInfo == null || iInfo == null) {
-                throw new HyracksDataException("Index with resource ID " + resourceID + " does not exist.");
-            }
+        if (dsInfo == null || iInfo == null) {
+            throw new HyracksDataException("Index with resource ID " + resourceID + " does not exist.");
+        }
 
-            opTracker = (PrimaryIndexOperationTracker) datasetOpTrackers.get(dsInfo.datasetID);
-            if (iInfo.referenceCount != 0 || (opTracker != null && opTracker.getNumActiveOperations() != 0)) {
-                throw new HyracksDataException("Cannot remove index while it is open.");
-            }
+        PrimaryIndexOperationTracker opTracker = (PrimaryIndexOperationTracker) datasetOpTrackers.get(dsInfo.datasetID);
+        if (iInfo.referenceCount != 0 || (opTracker != null && opTracker.getNumActiveOperations() != 0)) {
+            throw new HyracksDataException("Cannot remove index while it is open.");
+        }
 
-            while (dsInfo.numActiveIOOps > 0) {
-                try {
-                    wait();
-                } catch (InterruptedException e) {
-                    throw new HyracksDataException(e);
-                }
+        // TODO: use fine-grained counters, one for each index instead of a single counter per dataset.
+
+        // First wait for any ongoing IO operations
+        while (dsInfo.numActiveIOOps > 0) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                throw new HyracksDataException(e);
             }
         }
+
         if (iInfo.isOpen) {
-            iInfo.index.deactivate(true);
+            ILSMIndexAccessor accessor = (ILSMIndexAccessor) iInfo.index.createAccessor(NoOpOperationCallback.INSTANCE,
+                    NoOpOperationCallback.INSTANCE);
+            accessor.scheduleFlush(((BaseOperationTracker) iInfo.index.getOperationTracker()).getIOOperationCallback());
         }
 
-        synchronized (this) {
-            dsInfo.indexes.remove(resourceID);
-            if (dsInfo.referenceCount == 0 && dsInfo.isOpen && dsInfo.indexes.isEmpty()) {
-                List<IVirtualBufferCache> vbcs = getVirtualBufferCaches(did);
-                assert vbcs != null;
-                for (IVirtualBufferCache vbc : vbcs) {
-                    used -= (vbc.getNumPages() * vbc.getPageSize());
-                }
-                datasetInfos.remove(did);
+        // Then wait for above flush op. 
+        // They are separated so they don't deadlock each other.
+        while (dsInfo.numActiveIOOps > 0) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                throw new HyracksDataException(e);
             }
         }
+
+        if (iInfo.isOpen) {
+            iInfo.index.deactivate(false);
+        }
+
+        dsInfo.indexes.remove(resourceID);
+        if (dsInfo.referenceCount == 0 && dsInfo.isOpen && dsInfo.indexes.isEmpty()) {
+            List<IVirtualBufferCache> vbcs = getVirtualBufferCaches(did);
+            assert vbcs != null;
+            for (IVirtualBufferCache vbc : vbcs) {
+                used -= (vbc.getNumPages() * vbc.getPageSize());
+            }
+            datasetInfos.remove(did);
+        }
+
     }
 
     public synchronized void declareActiveIOOperation(int datasetID) throws HyracksDataException {
@@ -208,6 +222,25 @@
                     .get(dsInfo.datasetID);
             if (opTracker != null && opTracker.getNumActiveOperations() == 0 && dsInfo.referenceCount == 0
                     && dsInfo.isOpen) {
+
+                // First wait for any ongoing IO operations
+                while (dsInfo.numActiveIOOps > 0) {
+                    try {
+                        wait();
+                    } catch (InterruptedException e) {
+                        throw new HyracksDataException(e);
+                    }
+                }
+
+                for (IndexInfo iInfo : dsInfo.indexes.values()) {
+                    if (iInfo.isOpen) {
+                        ILSMIndexAccessor accessor = (ILSMIndexAccessor) iInfo.index.createAccessor(
+                                NoOpOperationCallback.INSTANCE, NoOpOperationCallback.INSTANCE);
+                        accessor.scheduleFlush(((BaseOperationTracker) iInfo.index.getOperationTracker())
+                                .getIOOperationCallback());
+                    }
+                }
+                // Wait for the above flush ops.
                 while (dsInfo.numActiveIOOps > 0) {
                     try {
                         wait();
@@ -217,20 +250,22 @@
                 }
                 for (IndexInfo iInfo : dsInfo.indexes.values()) {
                     if (iInfo.isOpen) {
-                        iInfo.index.deactivate(true);
+                        iInfo.index.deactivate(false);
                         iInfo.isOpen = false;
                     }
                     assert iInfo.referenceCount == 0;
                 }
+                dsInfo.isOpen = false;
 
                 List<IVirtualBufferCache> vbcs = getVirtualBufferCaches(dsInfo.datasetID);
                 for (IVirtualBufferCache vbc : vbcs) {
                     used -= vbc.getNumPages() * vbc.getPageSize();
                 }
-                dsInfo.isOpen = false;
                 return true;
+
             }
         }
+
         return false;
     }
 
@@ -267,10 +302,12 @@
             List<IVirtualBufferCache> vbcs = datasetVirtualBufferCaches.get(datasetID);
             if (vbcs == null) {
                 vbcs = new ArrayList<IVirtualBufferCache>();
-                for (int i = 0; i < NUM_MUTABLE_BUFFERS; i++) {
-                    MultitenantVirtualBufferCache vbc = new MultitenantVirtualBufferCache(new VirtualBufferCache(
-                            new HeapBufferAllocator(), storageProperties.getMemoryComponentPageSize(),
-                            datasetID < 100? storageProperties.getMemoryComponentNumPages(): 4 / NUM_MUTABLE_BUFFERS));
+                for (int i = 0; i < storageProperties.getMemoryComponentsNum(); i++) {
+                    MultitenantVirtualBufferCache vbc = new MultitenantVirtualBufferCache(
+                            new VirtualBufferCache(new HeapBufferAllocator(),
+                                    storageProperties.getMemoryComponentPageSize(),
+                                    storageProperties.getMemoryComponentNumPages()
+                                            / storageProperties.getMemoryComponentsNum()));
                     vbcs.add(vbc);
                 }
                 datasetVirtualBufferCaches.put(datasetID, vbcs);
diff --git a/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java b/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java
index ca9b232..861cce5 100644
--- a/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java
+++ b/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java
@@ -325,7 +325,8 @@
 
         List<CompilationUnit> cUnits = testCaseCtx.getTestCase().getCompilationUnit();
         for (CompilationUnit cUnit : cUnits) {
-            System.out.println(cUnit.getName());
+            LOGGER.info("Starting [TEST]: " + testCaseCtx.getTestCase().getFilePath() + "/"
+                    + cUnit.getName() + " ... ");
             testFileCtxs = testCaseCtx.getTestFiles(cUnit);
             expectedResultFileCtxs = testCaseCtx.getExpectedResultFiles(cUnit);
 
diff --git a/asterix-installer/src/main/resources/conf/asterix-configuration.xml b/asterix-installer/src/main/resources/conf/asterix-configuration.xml
index 6b3133c..deeb5b0 100644
--- a/asterix-installer/src/main/resources/conf/asterix-configuration.xml
+++ b/asterix-installer/src/main/resources/conf/asterix-configuration.xml
@@ -68,6 +68,14 @@
 		</description>
 	</property>
 
+    <property>
+		<name>storage.memorycomponent.numcomponents</name>
+		<value>2</value>
+		<description>The number of memory components to be used per lsm index.
+			(Default = 2)
+		</description>
+	</property>
+	
 	<property>
 		<name>storage.memorycomponent.globalbudget</name>
 		<value>536870192</value>