diff --git a/plugins/host-allocators/random/src/com/cloud/agent/manager/allocator/impl/RandomAllocator.java b/plugins/host-allocators/random/src/com/cloud/agent/manager/allocator/impl/RandomAllocator.java
index 5bdf4f1beaf..390a8afd089 100755
--- a/plugins/host-allocators/random/src/com/cloud/agent/manager/allocator/impl/RandomAllocator.java
+++ b/plugins/host-allocators/random/src/com/cloud/agent/manager/allocator/impl/RandomAllocator.java
@@ -61,6 +61,7 @@ public class RandomAllocator extends AdapterBase implements HostAllocator {
         Long clusterId = plan.getClusterId();
         ServiceOffering offering = vmProfile.getServiceOffering();
         List<Host> suitableHosts = new ArrayList<Host>();
+        List<Host> hostsCopy = new ArrayList<Host>(hosts);
 
         if (type == Host.Type.Storage) {
             return suitableHosts;
@@ -75,18 +76,18 @@ public class RandomAllocator extends AdapterBase implements HostAllocator {
 
         // list all computing hosts, regardless of whether they support routing...it's random after all
         if (hostTag != null) {
-            hosts.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, hostTag));
+            hostsCopy.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, hostTag));
         } else {
-            hosts.retainAll(_resourceMgr.listAllUpAndEnabledHosts(type, clusterId, podId, dcId));
+            hostsCopy.retainAll(_resourceMgr.listAllUpAndEnabledHosts(type, clusterId, podId, dcId));
         }
 
-        s_logger.debug("Random Allocator found " + hosts.size() + "  hosts");
-        if (hosts.size() == 0) {
+        s_logger.debug("Random Allocator found " + hostsCopy.size() + "  hosts");
+        if (hostsCopy.size() == 0) {
             return suitableHosts;
         }
 
-        Collections.shuffle(hosts);
-        for (Host host : hosts) {
+        Collections.shuffle(hostsCopy);
+        for (Host host : hostsCopy) {
             if (suitableHosts.size() == returnUpTo) {
                 break;
             }
diff --git a/server/src/com/cloud/agent/manager/allocator/impl/FirstFitAllocator.java b/server/src/com/cloud/agent/manager/allocator/impl/FirstFitAllocator.java
index a746eb756ca..990b77bc780 100755
--- a/server/src/com/cloud/agent/manager/allocator/impl/FirstFitAllocator.java
+++ b/server/src/com/cloud/agent/manager/allocator/impl/FirstFitAllocator.java
@@ -192,6 +192,7 @@ public class FirstFitAllocator extends AdapterBase implements HostAllocator {
         VMTemplateVO template = (VMTemplateVO)vmProfile.getTemplate();
         Account account = vmProfile.getOwner();
         List<Host> suitableHosts = new ArrayList<Host>();
+        List<Host> hostsCopy = new ArrayList<Host>(hosts);
 
         if (type == Host.Type.Storage) {
             // FirstFitAllocator should be used for user VMs only since it won't care whether the host is capable of
@@ -206,23 +207,38 @@ public class FirstFitAllocator extends AdapterBase implements HostAllocator {
 
         String haVmTag = (String)vmProfile.getParameter(VirtualMachineProfile.Param.HaTag);
         if (haVmTag != null) {
-            hosts.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, haVmTag));
+            hostsCopy.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, haVmTag));
         } else {
             if (hostTagOnOffering == null && hostTagOnTemplate == null) {
-                hosts.retainAll(_resourceMgr.listAllUpAndEnabledNonHAHosts(type, clusterId, podId, dcId));
+                hostsCopy.retainAll(_resourceMgr.listAllUpAndEnabledNonHAHosts(type, clusterId, podId, dcId));
             } else {
                 if (hasSvcOfferingTag) {
-                    hosts.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, hostTagOnOffering));
+                    if (s_logger.isDebugEnabled()) {
+                        s_logger.debug("Looking for hosts having tag specified on SvcOffering:" + hostTagOnOffering);
+                    }
+                    hostsCopy.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, hostTagOnOffering));
+
+                    if (s_logger.isDebugEnabled()) {
+                        s_logger.debug("Hosts with tag '" + hostTagOnOffering + "' are:" + hostsCopy);
+                    }
                 }
 
                 if (hasTemplateTag) {
-                    hosts.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, hostTagOnTemplate));
+                    if (s_logger.isDebugEnabled()) {
+                        s_logger.debug("Looking for hosts having tag specified on Template:" + hostTagOnTemplate);
+                    }
+
+                    hostsCopy.retainAll(_hostDao.listByHostTag(type, clusterId, podId, dcId, hostTagOnTemplate));
+
+                    if (s_logger.isDebugEnabled()) {
+                        s_logger.debug("Hosts with tag '" + hostTagOnTemplate + "' are:" + hostsCopy);
+                    }
                 }
             }
         }
 
-        if (!hosts.isEmpty()) {
-            suitableHosts = allocateTo(plan, offering, template, avoid, hosts, returnUpTo, considerReservedCapacity, account);
+        if (!hostsCopy.isEmpty()) {
+            suitableHosts = allocateTo(plan, offering, template, avoid, hostsCopy, returnUpTo, considerReservedCapacity, account);
         }
 
         return suitableHosts;