diff --git a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
index 1881d2f..2a64057 100644
--- a/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
+++ b/hyracks-storage-am-lsm-btree/src/main/java/edu/uci/ics/hyracks/storage/am/lsm/btree/impls/LSMBTree.java
@@ -501,11 +501,10 @@
         
         // Cleanup. At this point we have guaranteed that no searchers are
         // touching the old on-disk BTrees (localSearcherRefCount == 0).
-        for (BTree oldBTree : mergingDiskBTrees) {
-            oldBTree.close();
+        for (BTree oldBTree : mergingDiskBTrees) {            
             FileReference fileRef = diskFileMapProvider.lookupFileName(oldBTree.getFileId());
             diskBufferCache.closeFile(oldBTree.getFileId());
-            diskBufferCache.deleteFile(oldBTree.getFileId());
+            oldBTree.close();
             fileRef.getFile().delete();
         }
         isMerging.set(false);
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
new file mode 100644
index 0000000..911fff4
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTest.java
@@ -0,0 +1,61 @@
+/*
+ * 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.btree;
+
+import java.util.Random;
+
+import org.junit.After;
+import org.junit.Before;
+
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
+import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
+import edu.uci.ics.hyracks.storage.am.btree.tests.IOrderedIndexTestContext;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestContext;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.util.LSMBTreeTestHarness;
+
+@SuppressWarnings("rawtypes")
+public class LSMBTreeMergeTest extends LSMBTreeMergeTestDriver {
+    
+    public LSMBTreeMergeTest() {
+        super(LSMBTreeTestHarness.LEAF_FRAMES_TO_TEST);
+    }
+
+    private final LSMBTreeTestHarness harness = new LSMBTreeTestHarness();
+
+    @Before
+    public void setUp() throws HyracksDataException {
+        harness.setUp();
+    }
+
+    @After
+    public void tearDown() throws HyracksDataException {
+        harness.tearDown();
+    }
+
+    @Override
+    protected IOrderedIndexTestContext createTestContext(ISerializerDeserializer[] fieldSerdes, int numKeys,
+            BTreeLeafFrameType leafType) throws Exception {
+        return LSMBTreeTestContext.create(harness.getMemBufferCache(), harness.getMemFreePageManager(),
+                harness.getOnDiskDir(), harness.getDiskBufferCache(), harness.getDiskFileMapProvider(), fieldSerdes,
+                numKeys, harness.getFileId());
+    }
+
+    @Override
+    protected Random getRandom() {
+        return harness.getRandom();
+    }
+}
diff --git a/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTestDriver.java b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTestDriver.java
new file mode 100644
index 0000000..0113bff
--- /dev/null
+++ b/hyracks-tests/hyracks-storage-am-lsm-btree-test/src/test/java/edu/uci/ics/hyracks/storage/am/lsm/btree/LSMBTreeMergeTestDriver.java
@@ -0,0 +1,77 @@
+/*
+ * 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.btree;
+
+import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
+import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer;
+import edu.uci.ics.hyracks.dataflow.common.data.marshalling.UTF8StringSerializerDeserializer;
+import edu.uci.ics.hyracks.storage.am.btree.frames.BTreeLeafFrameType;
+import edu.uci.ics.hyracks.storage.am.btree.tests.IOrderedIndexTestContext;
+import edu.uci.ics.hyracks.storage.am.btree.tests.OrderedIndexTestDriver;
+import edu.uci.ics.hyracks.storage.am.btree.tests.OrderedIndexTestUtils;
+import edu.uci.ics.hyracks.storage.am.lsm.btree.impls.LSMBTree;
+
+@SuppressWarnings("rawtypes")
+public abstract class LSMBTreeMergeTestDriver extends OrderedIndexTestDriver {
+    
+    public LSMBTreeMergeTestDriver(BTreeLeafFrameType[] leafFrameTypesToTest) {
+        super(leafFrameTypesToTest);
+    }
+
+    @Override
+    protected void runTest(ISerializerDeserializer[] fieldSerdes, int numKeys, BTreeLeafFrameType leafType,
+            ITupleReference lowKey, ITupleReference highKey, ITupleReference prefixLowKey, ITupleReference prefixHighKey)
+            throws Exception {
+        IOrderedIndexTestContext ctx = createTestContext(fieldSerdes, numKeys, leafType);
+        
+        // Start off with one tree bulk loaded.
+        // We assume all fieldSerdes are of the same type. Check the first one
+        // to determine which field types to generate.
+        if (fieldSerdes[0] instanceof IntegerSerializerDeserializer) {
+            OrderedIndexTestUtils.bulkLoadIntTuples(ctx, numTuplesToInsert, getRandom());
+        } else if (fieldSerdes[0] instanceof UTF8StringSerializerDeserializer) {
+            OrderedIndexTestUtils.bulkLoadStringTuples(ctx, numTuplesToInsert, getRandom());
+        }
+        
+        int maxTreesToMerge = 10;
+        for (int i = 0; i < maxTreesToMerge; i++) {
+            for (int j = 0; j < i; j++) {
+                if (fieldSerdes[0] instanceof IntegerSerializerDeserializer) {
+                    OrderedIndexTestUtils.bulkLoadIntTuples(ctx, numTuplesToInsert, getRandom());
+                } else if (fieldSerdes[0] instanceof UTF8StringSerializerDeserializer) {
+                    OrderedIndexTestUtils.bulkLoadStringTuples(ctx, numTuplesToInsert, getRandom());
+                }
+            }
+
+            LSMBTree lsmBTree = (LSMBTree) ctx.getIndex();
+            lsmBTree.merge();
+            
+            OrderedIndexTestUtils.checkPointSearches(ctx);
+            OrderedIndexTestUtils.checkOrderedScan(ctx);
+            OrderedIndexTestUtils.checkDiskOrderScan(ctx);
+            OrderedIndexTestUtils.checkRangeSearch(ctx, lowKey, highKey, true, true);
+            if (prefixLowKey != null && prefixHighKey != null) {
+                OrderedIndexTestUtils.checkRangeSearch(ctx, prefixLowKey, prefixHighKey, true, true);
+            }
+        }
+    }
+
+    @Override
+    protected String getTestOpName() {
+        return "LSM Merge";
+    }
+}