diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/pom.xml b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/pom.xml
index bc1e146..37e1c49 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/pom.xml
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/pom.xml
@@ -82,8 +82,9 @@
       <artifactId>commons-lang3</artifactId>
     </dependency>
     <dependency>
-      <groupId>commons-io</groupId>
-      <artifactId>commons-io</artifactId>
+      <groupId>org.apache.hyracks</groupId>
+      <artifactId>hyracks-util</artifactId>
+      <version>${project.version}</version>
     </dependency>
   </dependencies>
 </project>
\ No newline at end of file
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/ILSMIndexFileManager.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/ILSMIndexFileManager.java
index 54d64af..18d9a67 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/ILSMIndexFileManager.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/api/ILSMIndexFileManager.java
@@ -34,28 +34,28 @@
  * merge).
  */
 public interface ILSMIndexFileManager {
-    public void createDirs();
+    void createDirs() throws HyracksDataException;
 
-    public void deleteDirs() throws HyracksDataException;
+    void deleteDirs() throws HyracksDataException;
 
-    public LSMComponentFileReferences getRelFlushFileReference() throws HyracksDataException;
+    LSMComponentFileReferences getRelFlushFileReference() throws HyracksDataException;
 
-    public LSMComponentFileReferences getRelMergeFileReference(String firstFileName, String lastFileName)
+    LSMComponentFileReferences getRelMergeFileReference(String firstFileName, String lastFileName)
             throws HyracksDataException;
 
-    public String getBaseDir();
+    String getBaseDir();
 
     // Deletes invalid files, and returns list of valid files from baseDir.
     // The returned valid files are correctly sorted (based on the recency of data).
-    public List<LSMComponentFileReferences> cleanupAndGetValidFiles() throws HyracksDataException;
+    List<LSMComponentFileReferences> cleanupAndGetValidFiles() throws HyracksDataException;
 
-    public Comparator<String> getFileNameComparator();
+    Comparator<String> getFileNameComparator();
 
     /**
      * @return delete existing transaction disk component file reference
      * @throws HyracksDataException
      */
-    public void deleteTransactionFiles() throws HyracksDataException;
+    void deleteTransactionFiles() throws HyracksDataException;
 
     /**
      * Rename files of a transaction removing the transaction prefix and return the component file reference in order to be committed
@@ -63,18 +63,18 @@
      * @return the renamed component file references
      * @throws HyracksDataException
      */
-    public LSMComponentFileReferences getTransactionFileReferenceForCommit() throws HyracksDataException;
+    LSMComponentFileReferences getTransactionFileReferenceForCommit() throws HyracksDataException;
 
     /**
      * Recover transaction files without returning them
      *
      * @throws HyracksDataException
      */
-    public void recoverTransaction() throws HyracksDataException;
+    void recoverTransaction() throws HyracksDataException;
 
     /**
      * @return a reference to the transaction disk component file reference
      * @throws IOException
      */
-    public LSMComponentFileReferences getNewTransactionFileReference() throws IOException;
+    LSMComponentFileReferences getNewTransactionFileReference() throws IOException;
 }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbortRecoverLSMIndexFileManager.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbortRecoverLSMIndexFileManager.java
index 090ca68..72d5423 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbortRecoverLSMIndexFileManager.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbortRecoverLSMIndexFileManager.java
@@ -23,6 +23,6 @@
 
 public class AbortRecoverLSMIndexFileManager extends AbstractLSMIndexFileManager {
     public AbortRecoverLSMIndexFileManager(IIOManager ioManager, FileReference file) {
-        super(ioManager, null, file, null);
+        super(ioManager, file, null);
     }
 }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
index 2be2184..c5bf2ca 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndex.java
@@ -63,7 +63,6 @@
 import org.apache.hyracks.storage.common.IModificationOperationCallback;
 import org.apache.hyracks.storage.common.ISearchOperationCallback;
 import org.apache.hyracks.storage.common.buffercache.IBufferCache;
-import org.apache.hyracks.storage.common.file.IFileMapProvider;
 
 public abstract class AbstractLSMIndex implements ILSMIndex {
     protected final ILSMHarness lsmHarness;
@@ -75,11 +74,9 @@
     protected final List<ILSMMemoryComponent> memoryComponents;
     protected final List<IVirtualBufferCache> virtualBufferCaches;
     protected AtomicInteger currentMutableComponentId;
-
     // On-disk components.
     protected final IBufferCache diskBufferCache;
     protected final ILSMIndexFileManager fileManager;
-    protected final IFileMapProvider diskFileMapProvider;
     // components with lower indexes are newer than components with higher index
     protected final List<ILSMDiskComponent> diskComponents;
     protected final List<ILSMDiskComponent> inactiveDiskComponents;
@@ -95,16 +92,14 @@
     protected boolean memoryComponentsAllocated = false;
 
     public AbstractLSMIndex(IIOManager ioManager, List<IVirtualBufferCache> virtualBufferCaches,
-            IBufferCache diskBufferCache, ILSMIndexFileManager fileManager, IFileMapProvider diskFileMapProvider,
-            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
-            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback,
-            ILSMComponentFilterFrameFactory filterFrameFactory, LSMComponentFilterManager filterManager,
-            int[] filterFields, boolean durable, IComponentFilterHelper filterHelper,
-            int[] treeFields) {
+            IBufferCache diskBufferCache, ILSMIndexFileManager fileManager, double bloomFilterFalsePositiveRate,
+            ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler,
+            ILSMIOOperationCallback ioOpCallback, ILSMComponentFilterFrameFactory filterFrameFactory,
+            LSMComponentFilterManager filterManager, int[] filterFields, boolean durable,
+            IComponentFilterHelper filterHelper, int[] treeFields) {
         this.ioManager = ioManager;
         this.virtualBufferCaches = virtualBufferCaches;
         this.diskBufferCache = diskBufferCache;
-        this.diskFileMapProvider = diskFileMapProvider;
         this.fileManager = fileManager;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.ioScheduler = ioScheduler;
@@ -130,12 +125,10 @@
 
     // The constructor used by external indexes
     public AbstractLSMIndex(IIOManager ioManager, IBufferCache diskBufferCache, ILSMIndexFileManager fileManager,
-            IFileMapProvider diskFileMapProvider, double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy,
-            ILSMOperationTracker opTracker, ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback,
-            boolean durable) {
+            double bloomFilterFalsePositiveRate, ILSMMergePolicy mergePolicy, ILSMOperationTracker opTracker,
+            ILSMIOOperationScheduler ioScheduler, ILSMIOOperationCallback ioOpCallback, boolean durable) {
         this.ioManager = ioManager;
         this.diskBufferCache = diskBufferCache;
-        this.diskFileMapProvider = diskFileMapProvider;
         this.fileManager = fileManager;
         this.bloomFilterFalsePositiveRate = bloomFilterFalsePositiveRate;
         this.ioScheduler = ioScheduler;
@@ -162,7 +155,6 @@
         if (isActive) {
             throw HyracksDataException.create(ErrorCode.CANNOT_CREATE_ACTIVE_INDEX);
         }
-        fileManager.deleteDirs();
         fileManager.createDirs();
         diskComponents.clear();
     }
@@ -238,16 +230,9 @@
             throw HyracksDataException.create(ErrorCode.CANNOT_DESTROY_ACTIVE_INDEX);
         }
         destroyDiskComponents();
-        destroyMemoryComponents();
         fileManager.deleteDirs();
     }
 
-    protected void destroyMemoryComponents() throws HyracksDataException {
-        for (ILSMMemoryComponent c : memoryComponents) {
-            destroyMemoryComponent(c);
-        }
-    }
-
     protected void destroyDiskComponents() throws HyracksDataException {
         List<ILSMDiskComponent> immutableComponents = diskComponents;
         for (ILSMDiskComponent c : immutableComponents) {
@@ -653,8 +638,6 @@
 
     protected abstract void destroyDiskComponent(ILSMDiskComponent c) throws HyracksDataException;
 
-    protected abstract void destroyMemoryComponent(ILSMMemoryComponent c) throws HyracksDataException;
-
     protected abstract void clearDiskComponent(ILSMDiskComponent c) throws HyracksDataException;
 
     protected abstract void clearMemoryComponent(ILSMMemoryComponent c) throws HyracksDataException;
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndexFileManager.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndexFileManager.java
index fca010f..ead9db4 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndexFileManager.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/AbstractLSMIndexFileManager.java
@@ -33,11 +33,11 @@
 import java.util.HashSet;
 import java.util.List;
 
-import org.apache.commons.io.FileUtils;
 import org.apache.hyracks.api.exceptions.ErrorCode;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.api.io.FileReference;
 import org.apache.hyracks.api.io.IIOManager;
+import org.apache.hyracks.api.util.IoUtil;
 import org.apache.hyracks.storage.am.common.api.ITreeIndex;
 import org.apache.hyracks.storage.am.common.api.ITreeIndexFrame;
 import org.apache.hyracks.storage.am.common.api.ITreeIndexMetadataFrame;
@@ -45,49 +45,63 @@
 import org.apache.hyracks.storage.common.buffercache.IBufferCache;
 import org.apache.hyracks.storage.common.buffercache.ICachedPage;
 import org.apache.hyracks.storage.common.file.BufferedFileHandle;
-import org.apache.hyracks.storage.common.file.IFileMapProvider;
 
 public abstract class AbstractLSMIndexFileManager implements ILSMIndexFileManager {
 
-    public static final String SPLIT_STRING = "_";
-    protected static final String BLOOM_FILTER_STRING = "f";
-    protected static final String TRANSACTION_PREFIX = ".T";
-
     public enum TreeIndexState {
         INVALID,
         VERSION_MISMATCH,
         VALID
     }
 
+    /**
+     * Split different parts of the file name
+     */
+    public static final String DELIMITER = "_";
+    /**
+     * Indicates a B tree
+     */
+    public static final String BTREE_SUFFIX = "b";
+    /**
+     * Indicates an R tree
+     */
+    public static final String RTREE_SUFFIX = "r";
+    /**
+     * Indicates a bloom filter
+     */
+    public static final String BLOOM_FILTER_SUFFIX = "f";
+    /**
+     * Indicates a delete tree
+     */
+    public static final String DELETE_TREE_SUFFIX = "d";
+    /**
+     * Hides transaction components until they are either committed by removing this file or deleted along with the file
+     */
+    public static final String TXN_PREFIX = ".T";
+
+    protected static final FilenameFilter fileNameFilter = (dir, name) -> !name.startsWith(".");
+    protected static final FilenameFilter txnFileNameFilter = (dir, name) -> name.startsWith(TXN_PREFIX);
+    protected static FilenameFilter bloomFilterFilter =
+            (dir, name) -> !name.startsWith(".") && name.endsWith(BLOOM_FILTER_SUFFIX);
+    protected static final FilenameFilter dummyFilter = (dir, name) -> true;
+    protected static final Comparator<String> cmp = new FileNameComparator();
+
     protected final IIOManager ioManager;
-    protected final IFileMapProvider fileMapProvider;
     // baseDir should reflect dataset name and partition name and be absolute
-    protected String baseDir;
+    protected final String baseDir;
     protected final Format formatter = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss-SSS");
-    protected final Comparator<String> cmp = new FileNameComparator();
     protected final Comparator<ComparableFileName> recencyCmp = new RecencyComparator();
     protected final TreeIndexFactory<? extends ITreeIndex> treeFactory;
-
     private String prevTimestamp = null;
 
-    public AbstractLSMIndexFileManager(IIOManager ioManager, IFileMapProvider fileMapProvider, FileReference file,
+    public AbstractLSMIndexFileManager(IIOManager ioManager, FileReference file,
             TreeIndexFactory<? extends ITreeIndex> treeFactory) {
         this.ioManager = ioManager;
-        this.baseDir = file.getFile().getAbsolutePath();
-        if (!baseDir.endsWith(System.getProperty("file.separator"))) {
-            baseDir += System.getProperty("file.separator");
-        }
-        this.fileMapProvider = fileMapProvider;
+        this.baseDir = file.getFile().getAbsolutePath().endsWith(File.separator) ? file.getFile().getAbsolutePath()
+                : file.getFile().getAbsolutePath() + File.separator;
         this.treeFactory = treeFactory;
     }
 
-    private static FilenameFilter fileNameFilter = new FilenameFilter() {
-        @Override
-        public boolean accept(File dir, String name) {
-            return !name.startsWith(".");
-        }
-    };
-
     protected TreeIndexState isValidTreeIndex(ITreeIndex treeIndex) throws HyracksDataException {
         IBufferCache bufferCache = treeIndex.getBufferCache();
         treeIndex.activate();
@@ -148,7 +162,7 @@
             if (!dir.canRead()) {
                 throw HyracksDataException.create(ErrorCode.CANNOT_READ_FILE, path);
             } else if (!dir.exists()) {
-                throw HyracksDataException.create(ErrorCode.FILE_DOES_NOT_EXISTS, path);
+                throw HyracksDataException.create(ErrorCode.FILE_DOES_NOT_EXIST, path);
             } else if (!dir.isDirectory()) {
                 throw HyracksDataException.create(ErrorCode.FILE_IS_NOT_DIRECTORY, path);
             }
@@ -162,44 +176,31 @@
         ArrayList<ComparableFileName> tmpAllInvListsFiles = new ArrayList<>();
         cleanupAndGetValidFilesInternal(filter, treeFactory, tmpAllInvListsFiles);
         for (ComparableFileName cmpFileName : tmpAllInvListsFiles) {
-            int index = cmpFileName.fileName.lastIndexOf(SPLIT_STRING);
+            int index = cmpFileName.fileName.lastIndexOf(DELIMITER);
             String file = cmpFileName.fileName.substring(0, index);
             if (groundTruth.contains(file)) {
                 validFiles.add(cmpFileName);
             } else {
                 File invalidFile = new File(cmpFileName.fullPath);
-                invalidFile.delete();
+                IoUtil.delete(invalidFile);
             }
         }
     }
 
     @Override
-    public void createDirs() {
+    public void createDirs() throws HyracksDataException {
         File f = new File(baseDir);
+        if (f.exists()) {
+            throw HyracksDataException.create(ErrorCode.CANNOT_CREATE_EXISTING_INDEX);
+        }
         f.mkdirs();
     }
 
     @Override
     public void deleteDirs() throws HyracksDataException {
-        File f = new File(baseDir);
-        if (f.exists()) {
-            delete(f);
-        }
+        IoUtil.delete(new File(baseDir));
     }
 
-    private void delete(File f) throws HyracksDataException {
-        if (!FileUtils.deleteQuietly(f)) {
-            throw HyracksDataException.create(ErrorCode.UNIDENTIFIED_IO_ERROR_DELETING_DIR, f.getPath());
-        }
-    }
-
-    protected static FilenameFilter bloomFilterFilter = new FilenameFilter() {
-        @Override
-        public boolean accept(File dir, String name) {
-            return !name.startsWith(".") && name.endsWith(BLOOM_FILTER_STRING);
-        }
-    };
-
     protected FileReference createFlushFile(String flushFileName) throws HyracksDataException {
         return ioManager.resolveAbsolutePath(flushFileName);
     }
@@ -212,17 +213,17 @@
     public LSMComponentFileReferences getRelFlushFileReference() throws HyracksDataException {
         String ts = getCurrentTimestamp();
         // Begin timestamp and end timestamp are identical since it is a flush
-        return new LSMComponentFileReferences(createFlushFile(baseDir + ts + SPLIT_STRING + ts), null, null);
+        return new LSMComponentFileReferences(createFlushFile(baseDir + ts + DELIMITER + ts), null, null);
     }
 
     @Override
     public LSMComponentFileReferences getRelMergeFileReference(String firstFileName, String lastFileName)
             throws HyracksDataException {
-        String[] firstTimestampRange = firstFileName.split(SPLIT_STRING);
-        String[] lastTimestampRange = lastFileName.split(SPLIT_STRING);
+        String[] firstTimestampRange = firstFileName.split(DELIMITER);
+        String[] lastTimestampRange = lastFileName.split(DELIMITER);
         // Get the range of timestamps by taking the earliest and the latest timestamps
         return new LSMComponentFileReferences(
-                createMergeFile(baseDir + firstTimestampRange[0] + SPLIT_STRING + lastTimestampRange[1]), null, null);
+                createMergeFile(baseDir + firstTimestampRange[0] + DELIMITER + lastTimestampRange[1]), null, null);
     }
 
     @Override
@@ -292,7 +293,7 @@
      * 2. Flushed files are sorted from newest to oldest (based on the timestamp
      * string)
      */
-    private class FileNameComparator implements Comparator<String> {
+    private static class FileNameComparator implements Comparator<String> {
         @Override
         public int compare(String a, String b) {
             // Consciously ignoring locale.
@@ -307,7 +308,7 @@
 
     @Override
     public void recoverTransaction() throws HyracksDataException {
-        String[] files = listDirFiles(baseDir, transactionFileNameFilter);
+        String[] files = listDirFiles(baseDir, txnFileNameFilter);
         File dir = new File(baseDir);
         try {
             if (files.length == 0) {
@@ -334,7 +335,7 @@
             this.fileRef = fileRef;
             this.fullPath = fileRef.getFile().getAbsolutePath();
             this.fileName = fileRef.getFile().getName();
-            interval = fileName.split(SPLIT_STRING);
+            interval = fileName.split(DELIMITER);
         }
 
         @Override
@@ -361,7 +362,7 @@
     // This function is used to delete transaction files for aborted transactions
     @Override
     public void deleteTransactionFiles() throws HyracksDataException {
-        String[] files = listDirFiles(baseDir, transactionFileNameFilter);
+        String[] files = listDirFiles(baseDir, txnFileNameFilter);
         if (files.length == 0) {
             // Do nothing
         } else if (files.length > 1) {
@@ -399,23 +400,9 @@
         return null;
     }
 
-    protected static FilenameFilter transactionFileNameFilter = new FilenameFilter() {
-        @Override
-        public boolean accept(File dir, String name) {
-            return name.startsWith(".T");
-        }
-    };
-
-    protected static FilenameFilter dummyFilter = new FilenameFilter() {
-        @Override
-        public boolean accept(File dir, String name) {
-            return true;
-        }
-    };
-
     protected static FilenameFilter createTransactionFilter(String transactionFileName, final boolean inclusive) {
-        final String timeStamp = transactionFileName
-                .substring(transactionFileName.indexOf(TRANSACTION_PREFIX) + TRANSACTION_PREFIX.length());
+        final String timeStamp =
+                transactionFileName.substring(transactionFileName.indexOf(TXN_PREFIX) + TXN_PREFIX.length());
         return new FilenameFilter() {
             @Override
             public boolean accept(File dir, String name) {
@@ -429,7 +416,7 @@
     }
 
     protected FilenameFilter getTransactionFileFilter(boolean inclusive) throws HyracksDataException {
-        String[] files = listDirFiles(baseDir, transactionFileNameFilter);
+        String[] files = listDirFiles(baseDir, txnFileNameFilter);
         if (files.length == 0) {
             return dummyFilter;
         } else {
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/BTreeFactory.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/BTreeFactory.java
index 562ed5a..4eefcd8 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/BTreeFactory.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/BTreeFactory.java
@@ -26,21 +26,20 @@
 import org.apache.hyracks.storage.am.common.api.IPageManagerFactory;
 import org.apache.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import org.apache.hyracks.storage.common.buffercache.IBufferCache;
-import org.apache.hyracks.storage.common.file.IFileMapProvider;
 
 public class BTreeFactory extends TreeIndexFactory<BTree> {
 
-    public BTreeFactory(IIOManager ioManager, IBufferCache bufferCache, IFileMapProvider fileMapProvider,
-            IPageManagerFactory freePageManagerFactory, ITreeIndexFrameFactory interiorFrameFactory,
-            ITreeIndexFrameFactory leafFrameFactory, IBinaryComparatorFactory[] cmpFactories, int fieldCount) {
-        super(ioManager, bufferCache, fileMapProvider, freePageManagerFactory, interiorFrameFactory, leafFrameFactory,
-                cmpFactories, fieldCount);
+    public BTreeFactory(IIOManager ioManager, IBufferCache bufferCache, IPageManagerFactory freePageManagerFactory,
+            ITreeIndexFrameFactory interiorFrameFactory, ITreeIndexFrameFactory leafFrameFactory,
+            IBinaryComparatorFactory[] cmpFactories, int fieldCount) {
+        super(ioManager, bufferCache, freePageManagerFactory, interiorFrameFactory, leafFrameFactory, cmpFactories,
+                fieldCount);
     }
 
     @Override
     public BTree createIndexInstance(FileReference file) {
-        return new BTree(bufferCache, fileMapProvider, freePageManagerFactory.createPageManager(bufferCache),
-                interiorFrameFactory, leafFrameFactory, cmpFactories, fieldCount, file);
+        return new BTree(bufferCache, freePageManagerFactory.createPageManager(bufferCache), interiorFrameFactory,
+                leafFrameFactory, cmpFactories, fieldCount, file);
     }
 
 }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/IndexFactory.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/IndexFactory.java
index 55fc92c..7a05d6d 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/IndexFactory.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/IndexFactory.java
@@ -25,20 +25,16 @@
 import org.apache.hyracks.storage.am.common.api.IPageManagerFactory;
 import org.apache.hyracks.storage.common.IIndex;
 import org.apache.hyracks.storage.common.buffercache.IBufferCache;
-import org.apache.hyracks.storage.common.file.IFileMapProvider;
 
 public abstract class IndexFactory<T extends IIndex> {
 
     protected final IIOManager ioManager;
     protected final IBufferCache bufferCache;
-    protected final IFileMapProvider fileMapProvider;
     protected final IPageManagerFactory freePageManagerFactory;
 
-    public IndexFactory(IIOManager ioManager, IBufferCache bufferCache, IFileMapProvider fileMapProvider,
-            IPageManagerFactory freePageManagerFactory) {
+    public IndexFactory(IIOManager ioManager, IBufferCache bufferCache, IPageManagerFactory freePageManagerFactory) {
         this.ioManager = ioManager;
         this.bufferCache = bufferCache;
-        this.fileMapProvider = fileMapProvider;
         this.freePageManagerFactory = freePageManagerFactory;
     }
 
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/MultitenantVirtualBufferCache.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/MultitenantVirtualBufferCache.java
index 6878fcf..83e140c 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/MultitenantVirtualBufferCache.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/MultitenantVirtualBufferCache.java
@@ -18,6 +18,8 @@
  */
 package org.apache.hyracks.storage.am.lsm.common.impls;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -29,6 +31,7 @@
 import org.apache.hyracks.storage.common.buffercache.IExtraPageBlockHelper;
 import org.apache.hyracks.storage.common.buffercache.IFIFOPageQueue;
 import org.apache.hyracks.storage.common.file.IFileMapManager;
+import org.apache.hyracks.util.JSONUtil;
 
 public class MultitenantVirtualBufferCache implements IVirtualBufferCache {
     private static final Logger LOGGER = Logger.getLogger(ExternalIndexHarness.class.getName());
@@ -42,8 +45,8 @@
     }
 
     @Override
-    public void createFile(FileReference fileRef) throws HyracksDataException {
-        vbc.createFile(fileRef);
+    public int createFile(FileReference fileRef) throws HyracksDataException {
+        return vbc.createFile(fileRef);
     }
 
     @Override
@@ -57,8 +60,8 @@
     }
 
     @Override
-    public void deleteFile(int fileId, boolean flushDirtyPages) throws HyracksDataException {
-        vbc.deleteFile(fileId, flushDirtyPages);
+    public void deleteFile(int fileId) throws HyracksDataException {
+        vbc.deleteFile(fileId);
     }
 
     @Override
@@ -91,6 +94,7 @@
         return vbc.getPageSize();
     }
 
+    @Override
     public int getPageSizeWithHeader() {
         return vbc.getPageSizeWithHeader();
     }
@@ -133,7 +137,7 @@
 
     @Override
     public int getNumPagesOfFile(int fileId) throws HyracksDataException {
-        throw new UnsupportedOperationException();
+        return vbc.getNumPagesOfFile(fileId);
     }
 
     @Override
@@ -205,4 +209,28 @@
             throws HyracksDataException {
         vbc.resizePage(page, multiplier, extraPageBlockHelper);
     }
+
+    @Override
+    public String toString() {
+        return JSONUtil.fromMap(toMap());
+    }
+
+    private Map<String, Object> toMap() {
+        HashMap<String, Object> map = new HashMap<>();
+        map.put("class", getClass().getSimpleName());
+        map.put("vbc", vbc.toString());
+        map.put("openCount", openCount);
+        return map;
+    }
+
+    @Override
+    public int openFile(FileReference fileRef) throws HyracksDataException {
+        return vbc.openFile(fileRef);
+    }
+
+    @Override
+    public void deleteFile(FileReference file) throws HyracksDataException {
+        vbc.deleteFile(file);
+    }
+
 }
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/TreeIndexFactory.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/TreeIndexFactory.java
index 2a7bcca..b6e2dd4 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/TreeIndexFactory.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/TreeIndexFactory.java
@@ -25,7 +25,6 @@
 import org.apache.hyracks.storage.am.common.api.ITreeIndex;
 import org.apache.hyracks.storage.am.common.api.ITreeIndexFrameFactory;
 import org.apache.hyracks.storage.common.buffercache.IBufferCache;
-import org.apache.hyracks.storage.common.file.IFileMapProvider;
 
 public abstract class TreeIndexFactory<T extends ITreeIndex> extends IndexFactory<T> {
 
@@ -34,10 +33,10 @@
     protected final IBinaryComparatorFactory[] cmpFactories;
     protected final int fieldCount;
 
-    public TreeIndexFactory(IIOManager ioManager, IBufferCache bufferCache, IFileMapProvider fileMapProvider,
-            IPageManagerFactory freePageManagerFactory, ITreeIndexFrameFactory interiorFrameFactory,
-            ITreeIndexFrameFactory leafFrameFactory, IBinaryComparatorFactory[] cmpFactories, int fieldCount) {
-        super(ioManager, bufferCache, fileMapProvider, freePageManagerFactory);
+    public TreeIndexFactory(IIOManager ioManager, IBufferCache bufferCache, IPageManagerFactory freePageManagerFactory,
+            ITreeIndexFrameFactory interiorFrameFactory, ITreeIndexFrameFactory leafFrameFactory,
+            IBinaryComparatorFactory[] cmpFactories, int fieldCount) {
+        super(ioManager, bufferCache, freePageManagerFactory);
         this.interiorFrameFactory = interiorFrameFactory;
         this.leafFrameFactory = leafFrameFactory;
         this.cmpFactories = cmpFactories;
diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
index 27d879c..83e377a 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-common/src/main/java/org/apache/hyracks/storage/am/lsm/common/impls/VirtualBufferCache.java
@@ -21,6 +21,8 @@
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
@@ -37,7 +39,8 @@
 import org.apache.hyracks.storage.common.buffercache.VirtualPage;
 import org.apache.hyracks.storage.common.file.BufferedFileHandle;
 import org.apache.hyracks.storage.common.file.IFileMapManager;
-import org.apache.hyracks.storage.common.file.TransientFileMapManager;
+import org.apache.hyracks.storage.common.file.FileMapManager;
+import org.apache.hyracks.util.JSONUtil;
 
 public class VirtualBufferCache implements IVirtualBufferCache {
     private static final Logger LOGGER = Logger.getLogger(ExternalIndexHarness.class.getName());
@@ -59,7 +62,7 @@
 
     public VirtualBufferCache(ICacheMemoryAllocator allocator, int pageSize, int numPages) {
         this.allocator = allocator;
-        this.fileMapManager = new TransientFileMapManager();
+        this.fileMapManager = new FileMapManager();
         this.pageSize = pageSize;
         this.numPages = 2 * (numPages / 2) + 1;
 
@@ -71,12 +74,19 @@
     }
 
     @Override
-    public void createFile(FileReference fileRef) throws HyracksDataException {
+    public int createFile(FileReference fileRef) throws HyracksDataException {
+        synchronized (fileMapManager) {
+            return fileMapManager.registerFile(fileRef);
+        }
+    }
+
+    @Override
+    public int openFile(FileReference fileRef) throws HyracksDataException {
         synchronized (fileMapManager) {
             if (fileMapManager.isMapped(fileRef)) {
-                throw new HyracksDataException("File " + fileRef + " is already mapped");
+                return fileMapManager.lookupFileId(fileRef);
             }
-            fileMapManager.registerFile(fileRef);
+            return fileMapManager.registerFile(fileRef);
         }
     }
 
@@ -89,14 +99,18 @@
     }
 
     @Override
-    public void deleteFile(int fileId, boolean flushDirtyPages) throws HyracksDataException {
+    public void deleteFile(FileReference fileRef) throws HyracksDataException {
         synchronized (fileMapManager) {
-            if (!fileMapManager.isMapped(fileId)) {
-                throw new HyracksDataException("File with id " + fileId + " is not mapped");
-            }
+            int fileId = fileMapManager.lookupFileId(fileRef);
+            deleteFile(fileId);
+        }
+    }
+
+    @Override
+    public void deleteFile(int fileId) throws HyracksDataException {
+        synchronized (fileMapManager) {
             fileMapManager.unregisterFile(fileId);
         }
-
         for (int i = 0; i < buckets.length; i++) {
             final CacheBucket bucket = buckets[i];
             bucket.bucketLock.lock();
@@ -185,8 +199,11 @@
             }
 
             if (!newPage) {
-                throw new HyracksDataException("Page " + BufferedFileHandle.getPageId(dpid) + " does not exist in file "
-                        + fileMapManager.lookupFileName(BufferedFileHandle.getFileId(dpid)));
+                synchronized (fileMapManager) {
+                    throw new HyracksDataException(
+                            "Page " + BufferedFileHandle.getPageId(dpid) + " does not exist in file "
+                                    + fileMapManager.lookupFileName(BufferedFileHandle.getFileId(dpid)));
+                }
             }
 
             page = getOrAllocPage(dpid);
@@ -355,12 +372,7 @@
 
     @Override
     public int getNumPagesOfFile(int fileId) throws HyracksDataException {
-        synchronized (fileMapManager) {
-            if (fileMapManager.isMapped(fileId)) {
-                return numPages;
-            }
-        }
-        return 0;
+        return -1;
     }
 
     @Override
@@ -424,7 +436,21 @@
 
     @Override
     public void purgeHandle(int fileId) throws HyracksDataException {
-
+        deleteFile(fileId);
     }
 
+    @Override
+    public String toString() {
+        return JSONUtil.fromMap(toMap());
+    }
+
+    private Map<String, Object> toMap() {
+        HashMap<String, Object> map = new HashMap<>();
+        map.put("class", getClass().getSimpleName());
+        map.put("allocator", allocator.toString());
+        map.put("pageSize", pageSize);
+        map.put("numPages", numPages);
+        map.put("open", open);
+        return map;
+    }
 }