diff --git a/storage/src/main/java/org/zstack/storage/addon/primary/ExternalPrimaryStorage.java b/storage/src/main/java/org/zstack/storage/addon/primary/ExternalPrimaryStorage.java
index 689c2510d9..b2db21cce5 100644
--- a/storage/src/main/java/org/zstack/storage/addon/primary/ExternalPrimaryStorage.java
+++ b/storage/src/main/java/org/zstack/storage/addon/primary/ExternalPrimaryStorage.java
@@ -18,6 +18,7 @@
 import org.zstack.core.workflow.FlowChainBuilder;
 import org.zstack.core.workflow.ShareFlow;
 import org.zstack.header.core.Completion;
+import org.zstack.header.core.NoErrorCompletion;
 import org.zstack.header.core.NopeCompletion;
 import org.zstack.header.core.ReturnValueCompletion;
 import org.zstack.header.core.WhileDoneCompletion;
@@ -172,7 +173,31 @@ protected void handleApiMessage(APIMessage msg) {
         }
     }
 
-    private void handle(APIUpdateExternalPrimaryStorageMsg msg) {
+    private void handle(final APIUpdateExternalPrimaryStorageMsg msg) {
+        thdf.chainSubmit(new ChainTask(msg) {
+            @Override
+            public String getSyncSignature() {
+                return String.format("update-external-primary-storage-%s", msg.getUuid());
+            }
+
+            @Override
+            public void run(SyncTaskChain chain) {
+                doUpdateExternalPrimaryStorageInQueue(msg, new NoErrorCompletion(chain) {
+                    @Override
+                    public void done() {
+                        chain.next();
+                    }
+                });
+            }
+
+            @Override
+            public String getName() {
+                return getSyncSignature();
+            }
+        });
+    }
+
+    private void doUpdateExternalPrimaryStorageInQueue(APIUpdateExternalPrimaryStorageMsg msg, NoErrorCompletion completion) {
         APIUpdateExternalPrimaryStorageEvent evt = new APIUpdateExternalPrimaryStorageEvent(msg.getId());
         if (msg.getName() != null) {
             externalVO.setName(msg.getName());
@@ -188,7 +213,7 @@ private void handle(APIUpdateExternalPrimaryStorageMsg msg) {
         }
         boolean needReconnect = false;
         String oldConfig = externalVO.getConfig();
-        if (msg.getConfig() != null) {
+        if (msg.getConfig() != null && !msg.getConfig().equals(oldConfig)) {
             String config = controller.validateConfig(msg.getConfig());
             externalVO.setConfig(config);
             needReconnect = true;
@@ -216,6 +241,7 @@ public void run(MessageReply reply) {
                     }
 
                     bus.publish(evt);
+                    completion.done();
                 }
             });
             return;
@@ -223,6 +249,7 @@ public void run(MessageReply reply) {
 
         evt.setInventory(externalVO.toInventory());
         bus.publish(evt);
+        completion.done();
     }
 
     @Override
diff --git a/test/src/test/groovy/org/zstack/test/integration/storage/primary/addon/zbs/ZbsPrimaryStorageCase.groovy b/test/src/test/groovy/org/zstack/test/integration/storage/primary/addon/zbs/ZbsPrimaryStorageCase.groovy
index d085ecec66..9b92f70e3e 100644
--- a/test/src/test/groovy/org/zstack/test/integration/storage/primary/addon/zbs/ZbsPrimaryStorageCase.groovy
+++ b/test/src/test/groovy/org/zstack/test/integration/storage/primary/addon/zbs/ZbsPrimaryStorageCase.groovy
@@ -1,9 +1,11 @@
 package org.zstack.test.integration.storage.primary.addon.zbs
 
 import org.springframework.http.HttpEntity
+import org.zstack.core.cloudbus.CloudBus
 import org.zstack.core.cloudbus.EventCallback
 import org.zstack.core.cloudbus.EventFacade
 import org.zstack.core.db.Q
+import org.zstack.core.thread.ThreadFacadeImpl
 import org.zstack.header.storage.addon.primary.ExternalPrimaryStorageVO
 import org.zstack.header.storage.addon.primary.ExternalPrimaryStorageSpaceVO
 import org.zstack.header.storage.addon.primary.ExternalPrimaryStorageVO_
@@ -13,6 +15,8 @@ import org.zstack.header.storage.primary.PrimaryStorageCapacityVO_
 import org.zstack.header.storage.primary.PrimaryStorageHostRefVO
 import org.zstack.header.storage.primary.PrimaryStorageHostRefVO_
 import org.zstack.header.storage.primary.PrimaryStorageStatus
+import org.zstack.header.storage.primary.ReconnectPrimaryStorageMsg
+import org.zstack.header.storage.primary.ReconnectPrimaryStorageReply
 import org.zstack.storage.zbs.MdsUri
 import org.zstack.sdk.*
 import org.zstack.storage.addon.primary.ExternalPrimaryStorageSystemTags
@@ -47,6 +51,8 @@ class ZbsPrimaryStorageCase extends SubCase {
     VolumeInventory vol, vol2
     KVMHostInventory kvm
     EventFacade evtf
+    ThreadFacadeImpl thdf
+    AtomicInteger reconnectMsgCount = new AtomicInteger(0)
 
     @Override
     void clean() {
@@ -165,6 +171,7 @@ class ZbsPrimaryStorageCase extends SubCase {
             diskOffering = env.inventoryByName("diskOffering") as DiskOfferingInventory
             kvm = env.inventoryByName("kvm-1") as KVMHostInventory
             evtf = bean(EventFacade.class)
+            thdf = bean(ThreadFacadeImpl.class)
 
             testSyncPrimaryStorageCapacityConcurrently()
             testDefaultConfig()
@@ -294,6 +301,53 @@ class ZbsPrimaryStorageCase extends SubCase {
         assert Q.New(ExternalPrimaryStorageSpaceVO.class)
                 .eq(ExternalPrimaryStorageSpaceVO_.primaryStorageUuid, ps.uuid)
                 .count() == 1
+
+        def signature = String.format("update-external-primary-storage-%s", ps.uuid)
+        def run = thdf.getChainTaskInfo(signature).getRunningTask().size()
+        retryInSecs {
+            assert thdf.getChainTaskInfo(signature).getRunningTask().size() == 0
+            assert thdf.getChainTaskInfo(signature).getPendingTask().size() == 0
+        }
+        env.message(ReconnectPrimaryStorageMsg.class) { ReconnectPrimaryStorageMsg msg, CloudBus bus ->
+            if (ps != null && msg.getPrimaryStorageUuid() == ps.uuid) {
+                reconnectMsgCount.incrementAndGet()
+                run = thdf.getChainTaskInfo(signature).getRunningTask().size()
+                assert run == 1
+            }
+            def reply = new ReconnectPrimaryStorageReply()
+            bus.reply(msg, reply)
+        }
+        def oldReconnectMsgCount=reconnectMsgCount.get()
+        String oldConfig = Q.New(ExternalPrimaryStorageVO.class)
+                .select(ExternalPrimaryStorageVO_.config)
+                .eq(ExternalPrimaryStorageVO_.uuid, ps.uuid)
+                .findValue()
+        Thread.start {
+            updateExternalPrimaryStorage {
+                uuid = ps.uuid
+                config = oldConfig
+            }
+        }
+        sleep(1000)
+        Thread.start {
+            updateExternalPrimaryStorage {
+                uuid = ps.uuid
+                config ="{\"mdsUrls\":[\"root:password@127.0.1.4\",\"root:password@127.0.1.2\",\"root:password@127.0.1.3\"],\"logicalPoolName\":\"lpool1\"}"
+            }
+        }
+        Thread.start {
+            updateExternalPrimaryStorage {
+                uuid = ps.uuid
+                config ="{\"mdsUrls\":[\"root:password@127.0.1.5\",\"root:password@127.0.1.2\",\"root:password@127.0.1.3\"],\"logicalPoolName\":\"lpool1\"}"
+            }
+        }
+        retryInSecs {
+            assert reconnectMsgCount.get() >=1
+            assert thdf.getChainTaskInfo(signature).getRunningTask().size() == 0
+            assert thdf.getChainTaskInfo(signature).getPendingTask().size() == 0
+        }
+        assert reconnectMsgCount.get() == oldReconnectMsgCount + 2
+        env.revokeMessage(ReconnectPrimaryStorageMsg.class, null)
         // update multi pools
         // Config.Pool
         updateExternalPrimaryStorage {