diff --git a/hyracks/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java b/hyracks/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java
index aa5ce1d..df140e3 100644
--- a/hyracks/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java
+++ b/hyracks/hyracks-examples/btree-example/btreehelper/src/main/java/edu/uci/ics/hyracks/examples/btree/helper/RuntimeContext.java
@@ -55,7 +55,7 @@
         resourceIdFactory = (new ResourceIdFactoryProvider(localResourceRepository)).createResourceIdFactory();
     }
 
-    public void close() {
+    public void close() throws HyracksDataException {
         bufferCache.close();
     }
 
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
index 35d6162..96a7404 100644
--- 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
@@ -1,10 +1,11 @@
 package edu.uci.ics.hyracks.storage.am.lsm.common.api;
 
+import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 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 void open() throws HyracksDataException;
 
     public boolean isFull();
 
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
index 1ad7f5d..4d9f8c2 100644
--- 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
@@ -72,7 +72,7 @@
     }
 
     @Override
-    public synchronized void close() {
+    public synchronized void close() throws HyracksDataException {
         --openCount;
         if (openCount == 0) {
             vbc.close();
@@ -80,9 +80,11 @@
     }
 
     @Override
-    public synchronized void open() {
+    public synchronized void open() throws HyracksDataException {
         ++openCount;
-        vbc.open();
+        if (openCount == 1) {
+            vbc.open();
+        }
     }
 
     @Override
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
index 1e0f34d..8123a89 100644
--- 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
@@ -212,9 +212,9 @@
     }
 
     @Override
-    public void open() {
+    public void open() throws HyracksDataException {
         if (open) {
-            return;
+            throw new HyracksDataException("Failed to open virtual buffercache since it is already open.");
         }
         pages.trimToSize();
         pages.ensureCapacity(numPages + OVERFLOW_PADDING);
@@ -243,9 +243,9 @@
     }
 
     @Override
-    public void close() {
+    public void close() throws HyracksDataException {
         if (!open) {
-            return;
+            throw new HyracksDataException("Failed to close virtual buffercache since it is already closed.");
         }
 
         pages.clear();
diff --git a/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/DebugBufferCache.java b/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/DebugBufferCache.java
index 13f7d52..81f3a26 100644
--- a/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/DebugBufferCache.java
+++ b/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/DebugBufferCache.java
@@ -99,7 +99,7 @@
     }
 
     @Override
-    public void close() {
+    public void close() throws HyracksDataException {
         bufferCache.close();
     }
 
@@ -156,13 +156,13 @@
         return closeFileCount.get();
     }
 
-	@Override
-	public void flushDirtyPage(ICachedPage page) throws HyracksDataException {
-		bufferCache.flushDirtyPage(page);
-	}
+    @Override
+    public void flushDirtyPage(ICachedPage page) throws HyracksDataException {
+        bufferCache.flushDirtyPage(page);
+    }
 
-	@Override
-	public void force(int fileId, boolean metadata) throws HyracksDataException {
-		bufferCache.force(fileId, metadata);
-	}
+    @Override
+    public void force(int fileId, boolean metadata) throws HyracksDataException {
+        bufferCache.force(fileId, metadata);
+    }
 }
diff --git a/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/IBufferCache.java b/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/IBufferCache.java
index e8b407e..9392ed9 100644
--- a/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/IBufferCache.java
+++ b/hyracks/hyracks-storage-common/src/main/java/edu/uci/ics/hyracks/storage/common/buffercache/IBufferCache.java
@@ -40,5 +40,5 @@
 
     public int getNumPages();
 
-    public void close();
+    public void close() throws HyracksDataException;
 }
\ No newline at end of file
diff --git a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
index 8d6ab38..0f4afd3 100644
--- a/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
+++ b/pregelix/pregelix-dataflow/src/main/java/edu/uci/ics/pregelix/dataflow/context/RuntimeContext.java
@@ -75,7 +75,7 @@
         resourceIdFactory = new ResourceIdFactory(0);
     }
 
-    public void close() {
+    public void close() throws HyracksDataException {
         for (Entry<Long, List<FileReference>> entry : iterationToFiles.entrySet())
             for (FileReference fileRef : entry.getValue())
                 fileRef.delete();