diff --git a/pregelix/pregelix-runtime/pom.xml b/pregelix/pregelix-runtime/pom.xml
index 6564eb0..245c0f5 100644
--- a/pregelix/pregelix-runtime/pom.xml
+++ b/pregelix/pregelix-runtime/pom.xml
@@ -141,6 +141,13 @@
 		</dependency>
 		<dependency>
 			<groupId>edu.uci.ics.hyracks</groupId>
+			<artifactId>hyracks-storage-common</artifactId>
+			<version>0.2.10-SNAPSHOT</version>
+			<type>jar</type>
+			<scope>compile</scope>
+		</dependency>
+		<dependency>
+			<groupId>edu.uci.ics.hyracks</groupId>
 			<artifactId>hyracks-storage-am-btree</artifactId>
 			<version>0.2.10-SNAPSHOT</version>
 			<type>jar</type>
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java
index f3a0bb4..b1d1043 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/ComputeUpdateFunctionFactory.java
@@ -31,6 +31,9 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 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.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPageInternal;
 import edu.uci.ics.pregelix.api.graph.GlobalAggregator;
 import edu.uci.ics.pregelix.api.graph.MsgList;
 import edu.uci.ics.pregelix.api.graph.Vertex;
@@ -110,7 +113,8 @@
             public void open(IHyracksTaskContext ctx, RecordDescriptor rd, IFrameWriter... writers)
                     throws HyracksDataException {
                 this.conf = confFactory.createConfiguration(ctx);
-                this.dynamicStateLength = BspUtils.getDynamicVertexValueSize(conf);
+                //LSM index does not have in-place update
+                this.dynamicStateLength = BspUtils.getDynamicVertexValueSize(conf) || BspUtils.useLSM(conf);
                 this.aggregator = BspUtils.createGlobalAggregator(conf);
                 this.aggregator.init();
 
@@ -262,7 +266,8 @@
             }
 
             @Override
-            public void update(ITupleReference tupleRef, ArrayTupleBuilder cloneUpdateTb) throws HyracksDataException {
+            public void update(ITupleReference tupleRef, ArrayTupleBuilder cloneUpdateTb, IIndexCursor cursor)
+                    throws HyracksDataException {
                 try {
                     if (vertex != null && vertex.hasUpdate()) {
                         if (!dynamicStateLength) {
@@ -271,12 +276,16 @@
                             int offset = tupleRef.getFieldStart(1);
                             bbos.setByteArray(data, offset);
                             vertex.write(output);
+
+                            BTreeRangeSearchCursor btreeCursor = (BTreeRangeSearchCursor) cursor;
+                            ICachedPageInternal page = (ICachedPageInternal) btreeCursor.getPage();
+                            //IMPORTANT: mark the page to be dirty
+                            page.markDirty();
                         } else {
                             // write the vertex id
                             DataOutput tbOutput = cloneUpdateTb.getDataOutput();
                             vertex.getVertexId().write(tbOutput);
                             cloneUpdateTb.addFieldEndOffset();
-
                             // write the vertex value
                             vertex.write(tbOutput);
                             cloneUpdateTb.addFieldEndOffset();
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/NoOpUpdateFunctionFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/NoOpUpdateFunctionFactory.java
index 88577c2..8947c01 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/NoOpUpdateFunctionFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/NoOpUpdateFunctionFactory.java
@@ -20,6 +20,7 @@
 import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.data.accessors.ITupleReference;
+import edu.uci.ics.hyracks.storage.am.common.api.IIndexCursor;
 import edu.uci.ics.pregelix.dataflow.std.base.IUpdateFunction;
 import edu.uci.ics.pregelix.dataflow.std.base.IUpdateFunctionFactory;
 
@@ -57,7 +58,8 @@
             }
 
             @Override
-            public void update(ITupleReference tupleRef, ArrayTupleBuilder cloneUpdateTb) throws HyracksDataException {
+            public void update(ITupleReference tupleRef, ArrayTupleBuilder cloneUpdateTb, IIndexCursor cursor)
+                    throws HyracksDataException {
 
             }
 
diff --git a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java
index ca8ec01..05b4e87 100644
--- a/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java
+++ b/pregelix/pregelix-runtime/src/main/java/edu/uci/ics/pregelix/runtime/function/StartComputeUpdateFunctionFactory.java
@@ -31,6 +31,9 @@
 import edu.uci.ics.hyracks.dataflow.common.comm.io.ArrayTupleBuilder;
 import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAppender;
 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.common.api.IIndexCursor;
+import edu.uci.ics.hyracks.storage.common.buffercache.ICachedPageInternal;
 import edu.uci.ics.pregelix.api.graph.GlobalAggregator;
 import edu.uci.ics.pregelix.api.graph.MsgList;
 import edu.uci.ics.pregelix.api.graph.Vertex;
@@ -113,7 +116,8 @@
             public void open(IHyracksTaskContext ctx, RecordDescriptor rd, IFrameWriter... writers)
                     throws HyracksDataException {
                 this.conf = confFactory.createConfiguration(ctx);
-                this.dynamicStateLength = BspUtils.getDynamicVertexValueSize(conf);
+                //LSM index does not have in-place update
+                this.dynamicStateLength = BspUtils.getDynamicVertexValueSize(conf) || BspUtils.useLSM(conf);;
                 this.aggregator = BspUtils.createGlobalAggregator(conf);
                 this.aggregator.init();
 
@@ -255,7 +259,8 @@
             }
 
             @Override
-            public void update(ITupleReference tupleRef, ArrayTupleBuilder cloneUpdateTb) throws HyracksDataException {
+            public void update(ITupleReference tupleRef, ArrayTupleBuilder cloneUpdateTb, IIndexCursor cursor)
+                    throws HyracksDataException {
                 try {
                     if (vertex != null && vertex.hasUpdate()) {
                         if (!dynamicStateLength) {
@@ -264,6 +269,11 @@
                             int offset = tupleRef.getFieldStart(1);
                             bbos.setByteArray(data, offset);
                             vertex.write(output);
+
+                            BTreeRangeSearchCursor btreeCursor = (BTreeRangeSearchCursor) cursor;
+                            ICachedPageInternal page = (ICachedPageInternal) btreeCursor.getPage();
+                            //IMPORTANT: mark the page to be dirty
+                            page.markDirty();
                         } else {
                             // write the vertex id
                             DataOutput tbOutput = cloneUpdateTb.getDataOutput();