diff --git a/engine/schema/src/org/apache/cloudstack/storage/datastore/db/SnapshotDataStoreVO.java b/engine/schema/src/org/apache/cloudstack/storage/datastore/db/SnapshotDataStoreVO.java
index 8b68d6c9038..75b1d75dd6a 100644
--- a/engine/schema/src/org/apache/cloudstack/storage/datastore/db/SnapshotDataStoreVO.java
+++ b/engine/schema/src/org/apache/cloudstack/storage/datastore/db/SnapshotDataStoreVO.java
@@ -29,6 +29,8 @@ import javax.persistence.Table;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
 
+import org.apache.log4j.Logger;
+
 import org.apache.cloudstack.engine.subsystem.api.storage.DataObjectInStore;
 import org.apache.cloudstack.engine.subsystem.api.storage.ObjectInDataStoreStateMachine;
 import org.apache.cloudstack.engine.subsystem.api.storage.ObjectInDataStoreStateMachine.State;
@@ -44,6 +46,8 @@ import com.cloud.utils.fsm.StateObject;
 @Entity
 @Table(name = "snapshot_store_ref")
 public class SnapshotDataStoreVO implements StateObject<ObjectInDataStoreStateMachine.State>, DataObjectInStore {
+    private static final Logger s_logger = Logger.getLogger(SnapshotDataStoreVO.class);
+
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     Long id;
@@ -272,7 +276,12 @@ public class SnapshotDataStoreVO implements StateObject<ObjectInDataStoreStateMa
     }
 
     public void decrRefCnt() {
-        refCnt--;
+        if (refCnt > 0) {
+            refCnt--;
+        }
+        else {
+            s_logger.warn("We should not try to decrement a zero reference count even though our code has guarded");
+        }
     }
 
     public Long getVolumeId() {
diff --git a/engine/schema/src/org/apache/cloudstack/storage/datastore/db/TemplateDataStoreVO.java b/engine/schema/src/org/apache/cloudstack/storage/datastore/db/TemplateDataStoreVO.java
index 897fee0e4de..bb40bf5d11a 100755
--- a/engine/schema/src/org/apache/cloudstack/storage/datastore/db/TemplateDataStoreVO.java
+++ b/engine/schema/src/org/apache/cloudstack/storage/datastore/db/TemplateDataStoreVO.java
@@ -29,6 +29,8 @@ import javax.persistence.Table;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
 
+import org.apache.log4j.Logger;
+
 import org.apache.cloudstack.engine.subsystem.api.storage.DataObjectInStore;
 import org.apache.cloudstack.engine.subsystem.api.storage.ObjectInDataStoreStateMachine;
 import org.apache.cloudstack.engine.subsystem.api.storage.ObjectInDataStoreStateMachine.State;
@@ -45,6 +47,8 @@ import com.cloud.utils.fsm.StateObject;
 @Entity
 @Table(name = "template_store_ref")
 public class TemplateDataStoreVO implements StateObject<ObjectInDataStoreStateMachine.State>, DataObjectInStore {
+    private static final Logger s_logger = Logger.getLogger(TemplateDataStoreVO.class);
+
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     Long id;
@@ -367,7 +371,12 @@ public class TemplateDataStoreVO implements StateObject<ObjectInDataStoreStateMa
     }
 
     public void decrRefCnt() {
-        refCnt--;
+        if (refCnt > 0) {
+            refCnt--;
+        }
+        else{
+            s_logger.warn("We should not try to decrement a zero reference count even though our code has guarded");
+        }
     }
 
 }
diff --git a/engine/schema/src/org/apache/cloudstack/storage/datastore/db/VolumeDataStoreVO.java b/engine/schema/src/org/apache/cloudstack/storage/datastore/db/VolumeDataStoreVO.java
index fe6aca4c3d2..588eae8ba57 100755
--- a/engine/schema/src/org/apache/cloudstack/storage/datastore/db/VolumeDataStoreVO.java
+++ b/engine/schema/src/org/apache/cloudstack/storage/datastore/db/VolumeDataStoreVO.java
@@ -29,6 +29,8 @@ import javax.persistence.Table;
 import javax.persistence.Temporal;
 import javax.persistence.TemporalType;
 
+import org.apache.log4j.Logger;
+
 import org.apache.cloudstack.engine.subsystem.api.storage.DataObjectInStore;
 import org.apache.cloudstack.engine.subsystem.api.storage.ObjectInDataStoreStateMachine;
 import org.apache.cloudstack.engine.subsystem.api.storage.ObjectInDataStoreStateMachine.State;
@@ -44,6 +46,8 @@ import com.cloud.utils.fsm.StateObject;
 @Entity
 @Table(name = "volume_store_ref")
 public class VolumeDataStoreVO implements StateObject<ObjectInDataStoreStateMachine.State>, DataObjectInStore {
+    private static final Logger s_logger = Logger.getLogger(VolumeDataStoreVO.class);
+
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     Long id;
@@ -342,7 +346,12 @@ public class VolumeDataStoreVO implements StateObject<ObjectInDataStoreStateMach
     }
 
     public void setRefCnt(Long refCnt) {
-        this.refCnt = refCnt;
+        if (refCnt > 0) {
+            refCnt--;
+        }
+        else {
+            s_logger.warn("We should not try to decrement a zero reference count even though our code has guarded");
+        }
     }
 
     public void incrRefCnt() {