diff --git a/compute/src/main/java/org/zstack/compute/vm/VmNicManagerImpl.java b/compute/src/main/java/org/zstack/compute/vm/VmNicManagerImpl.java
index 25c0b005d71..31b3e35d32a 100644
--- a/compute/src/main/java/org/zstack/compute/vm/VmNicManagerImpl.java
+++ b/compute/src/main/java/org/zstack/compute/vm/VmNicManagerImpl.java
@@ -58,6 +58,10 @@ public void afterAddIpAddress(String vmNicUUid, String usedIpUuid) {
         SQL.New(UsedIpVO.class).eq(UsedIpVO_.uuid, usedIpUuid).set(UsedIpVO_.vmNicUuid, vmNicUUid).update();
 
         VmNicVO nic = Q.New(VmNicVO.class).eq(VmNicVO_.uuid, vmNicUUid).find();
+        if (nic == null) {
+            logger.debug(String.format("VmNic[uuid:%s] not found, skip afterAddIpAddress", vmNicUUid));
+            return;
+        }
 
         UsedIpVO temp = null;
         /* if there is ipv4 addresses, we put the first attached ipv4 address to VmNic.ip
@@ -88,6 +92,10 @@ public void afterAddIpAddress(String vmNicUUid, String usedIpUuid) {
     @Override
     public void afterDelIpAddress(String vmNicUUid, String usedIpUuid) {
         VmNicVO nic = Q.New(VmNicVO.class).eq(VmNicVO_.uuid, vmNicUUid).find();
+        if (nic == null) {
+            logger.debug(String.format("VmNic[uuid:%s] not found, skip afterDelIpAddress", vmNicUUid));
+            return;
+        }
         if (nic.getUsedIpUuid() != null && !nic.getUsedIpUuid().equals(usedIpUuid)) {
             return;
         }
diff --git a/conf/i18n/globalErrorCodeMapping/global-error-en_US.json b/conf/i18n/globalErrorCodeMapping/global-error-en_US.json
index 32eb4c8f056..715e823d95e 100644
--- a/conf/i18n/globalErrorCodeMapping/global-error-en_US.json
+++ b/conf/i18n/globalErrorCodeMapping/global-error-en_US.json
@@ -3374,7 +3374,7 @@
   "ORG_ZSTACK_NETWORK_HUAWEI_IMASTER_10019": "delete token of SDN controller [IP:%s] failed because %s",
   "ORG_ZSTACK_STORAGE_PRIMARY_BLOCK_10004": "Cannot execute volume mapping to host flow due to invalid volume ID.%s",
   "ORG_ZSTACK_NETWORK_SERVICE_PORTFORWARDING_10007": "port forwarding rule [uuid:%s] has not been attached to any virtual machine network interface, cannot detach",
-  "ORG_ZSTACK_MEVOCO_10088": "cannot take a snapshot for volumes[%s] when volume[uuid: %s] is not attached",
+  "ORG_ZSTACK_MEVOCO_10088": "cannot create snapshot for volume[uuid:%s] because it is not attached to any VM instance. Please attach the volume to a VM first. Affected volumes: %s",
   "ORG_ZSTACK_STORAGE_PRIMARY_BLOCK_10005": "Cannot execute map LUN to host flow due to invalid LUN type: %s",
   "ORG_ZSTACK_NETWORK_SERVICE_PORTFORWARDING_10008": "port forwarding rule [uuid:%s] has been associated with vm nic [uuid:%s], cannot be reassigned again",
   "ORG_ZSTACK_MEVOCO_10087": "A Running VM[uuid:%s] has no associated Host UUID.",
diff --git a/conf/i18n/globalErrorCodeMapping/global-error-zh_CN.json b/conf/i18n/globalErrorCodeMapping/global-error-zh_CN.json
index 84609838ddc..01960e8eb45 100644
--- a/conf/i18n/globalErrorCodeMapping/global-error-zh_CN.json
+++ b/conf/i18n/globalErrorCodeMapping/global-error-zh_CN.json
@@ -3374,7 +3374,7 @@
   "ORG_ZSTACK_NETWORK_HUAWEI_IMASTER_10019": "删除 SDN 控制器 [IP：%s] 的令牌失败，因为 %s",
   "ORG_ZSTACK_STORAGE_PRIMARY_BLOCK_10004": "无法执行映射LUN到主机流程，无效的LUN ID",
   "ORG_ZSTACK_NETWORK_SERVICE_PORTFORWARDING_10007": "端口转发规则 rule[uuid:%s] 没有绑定到任何 VM 的网卡上，无法解除绑定",
-  "ORG_ZSTACK_MEVOCO_10088": "无法为挂载状态以外的卷[%s]创建快照",
+  "ORG_ZSTACK_MEVOCO_10088": "无法为云盘[uuid:%s]创建快照，因为该云盘未挂载到任何云主机。请先将云盘挂载到云主机后再创建快照。相关云盘: %s",
   "ORG_ZSTACK_STORAGE_PRIMARY_BLOCK_10005": "无法执行映射LUN到主机流程，无效的LUN类型",
   "ORG_ZSTACK_NETWORK_SERVICE_PORTFORWARDING_10008": "端口转发规则[uuid:%s]已绑定到VM网卡[uuid:%s]，无法再次绑定",
   "ORG_ZSTACK_MEVOCO_10087": "如何一个运行中的VM[uuid:%s]没有宿主机uuid?",
diff --git a/core/src/main/java/org/zstack/core/cloudbus/ResourceDestinationMakerImpl.java b/core/src/main/java/org/zstack/core/cloudbus/ResourceDestinationMakerImpl.java
index 08a776f1db2..9ead578395d 100755
--- a/core/src/main/java/org/zstack/core/cloudbus/ResourceDestinationMakerImpl.java
+++ b/core/src/main/java/org/zstack/core/cloudbus/ResourceDestinationMakerImpl.java
@@ -27,27 +27,27 @@ public class ResourceDestinationMakerImpl implements ManagementNodeChangeListene
     private DatabaseFacade dbf;
 
     @Override
-    public void nodeJoin(ManagementNodeInventory inv) {
+    public synchronized void nodeJoin(ManagementNodeInventory inv) {
         nodeHash.add(inv.getUuid());
         nodes.put(inv.getUuid(), new NodeInfo(inv));
     }
 
     @Override
-    public void nodeLeft(ManagementNodeInventory inv) {
+    public synchronized void nodeLeft(ManagementNodeInventory inv) {
         String nodeId = inv.getUuid();
         nodeHash.remove(nodeId);
         nodes.remove(nodeId);
     }
 
     @Override
-    public void iAmDead(ManagementNodeInventory inv) {
+    public synchronized void iAmDead(ManagementNodeInventory inv) {
         String nodeId = inv.getUuid();
         nodeHash.remove(nodeId);
         nodes.remove(nodeId);
     }
 
     @Override
-    public void iJoin(ManagementNodeInventory inv) {
+    public synchronized void iJoin(ManagementNodeInventory inv) {
         List<ManagementNodeVO> lst = Q.New(ManagementNodeVO.class).list();
         lst.forEach((ManagementNodeVO node) -> {
             nodeHash.add(node.getUuid());
@@ -56,7 +56,7 @@ public void iJoin(ManagementNodeInventory inv) {
     }
 
     @Override
-    public String makeDestination(String resourceUuid) {
+    public synchronized String makeDestination(String resourceUuid) {
         String nodeUuid = nodeHash.get(resourceUuid);
         if (nodeUuid == null) {
             throw new CloudRuntimeException("Cannot find any available management node to send message");
@@ -66,18 +66,18 @@ public String makeDestination(String resourceUuid) {
     }
 
     @Override
-    public boolean isManagedByUs(String resourceUuid) {
+    public synchronized boolean isManagedByUs(String resourceUuid) {
         String nodeUuid = makeDestination(resourceUuid);
         return nodeUuid.equals(Platform.getManagementServerId());
     }
 
     @Override
-    public Collection<String> getManagementNodesInHashRing() {
-        return nodeHash.getNodes();
+    public synchronized Collection<String> getManagementNodesInHashRing() {
+        return new ArrayList<>(nodeHash.getNodes());
     }
 
     @Override
-    public NodeInfo getNodeInfo(String nodeUuid) {
+    public synchronized NodeInfo getNodeInfo(String nodeUuid) {
         NodeInfo info = nodes.get(nodeUuid);
         if (info == null) {
             ManagementNodeVO vo = dbf.findByUuid(nodeUuid, ManagementNodeVO.class);
@@ -93,17 +93,17 @@ public NodeInfo getNodeInfo(String nodeUuid) {
     }
 
     @Override
-    public Collection<NodeInfo> getAllNodeInfo() {
-        return nodes.values();
+    public synchronized Collection<NodeInfo> getAllNodeInfo() {
+        return new ArrayList<>(nodes.values());
     }
 
     @Override
-    public int getManagementNodeCount() {
-        return nodes.values().size();
+    public synchronized int getManagementNodeCount() {
+        return nodes.size();
     }
 
 
-    public boolean isNodeInCircle(String nodeId) {
+    public synchronized boolean isNodeInCircle(String nodeId) {
         return nodeHash.hasNode(nodeId);
     }
 }
diff --git a/core/src/main/java/org/zstack/core/thread/DispatchQueueImpl.java b/core/src/main/java/org/zstack/core/thread/DispatchQueueImpl.java
index e298cdd787f..961b192ac7c 100755
--- a/core/src/main/java/org/zstack/core/thread/DispatchQueueImpl.java
+++ b/core/src/main/java/org/zstack/core/thread/DispatchQueueImpl.java
@@ -302,7 +302,7 @@ private class SyncTaskFuture<T> extends AbstractFuture<T> {
 
         public SyncTaskFuture(SyncTask<T> task) {
             super(task);
-            this.parentContext = Context.current();
+            this.parentContext = isTelemetryEnabled() ? Context.current() : null;
         }
 
         private SyncTask getTask() {
diff --git a/header/src/main/java/org/zstack/header/storage/addon/primary/ExternalPrimaryStorageInventory.java b/header/src/main/java/org/zstack/header/storage/addon/primary/ExternalPrimaryStorageInventory.java
index 7808c227623..a15ed211307 100644
--- a/header/src/main/java/org/zstack/header/storage/addon/primary/ExternalPrimaryStorageInventory.java
+++ b/header/src/main/java/org/zstack/header/storage/addon/primary/ExternalPrimaryStorageInventory.java
@@ -4,8 +4,10 @@
 import org.zstack.header.storage.primary.PrimaryStorageInventory;
 import org.zstack.utils.gson.JSONObjectUtil;
 
+import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 @Inventory(mappingVOClass = ExternalPrimaryStorageVO.class)
@@ -59,6 +61,7 @@ public ExternalPrimaryStorageInventory(ExternalPrimaryStorageVO lvo) {
         super(lvo);
         identity = lvo.getIdentity();
         config = JSONObjectUtil.toObject(lvo.getConfig(), LinkedHashMap.class);
+        desensitizeConfig(config);
         addonInfo = JSONObjectUtil.toObject(lvo.getAddonInfo(), LinkedHashMap.class);
         outputProtocols = lvo.getOutputProtocols().stream().map(PrimaryStorageOutputProtocolRefVO::getOutputProtocol).collect(Collectors.toList());
         defaultProtocol = lvo.getDefaultProtocol();
@@ -68,6 +71,35 @@ public static ExternalPrimaryStorageInventory valueOf(ExternalPrimaryStorageVO l
         return new ExternalPrimaryStorageInventory(lvo);
     }
 
+    private static void desensitizeConfig(Map config) {
+        if (config == null) return;
+        desensitizeUrlList(config, "mdsUrls");
+        desensitizeUrlList(config, "mdsInfos");
+    }
+
+    private static void desensitizeUrlList(Map config, String key) {
+        Object urls = config.get(key);
+        if (urls instanceof List) {
+            List<String> desensitized = new ArrayList<>();
+            for (Object url : (List) urls) {
+                desensitized.add(desensitizeUrl(String.valueOf(url)));
+            }
+            config.put(key, desensitized);
+        }
+    }
+
+    private static String desensitizeUrl(String url) {
+        int atIndex = url.lastIndexOf('@');
+        if (atIndex > 0) {
+            int schemeIndex = url.indexOf("://");
+            if (schemeIndex >= 0 && schemeIndex < atIndex) {
+                return url.substring(0, schemeIndex + 3) + "***" + url.substring(atIndex);
+            }
+            return "***" + url.substring(atIndex);
+        }
+        return url;
+    }
+
     public String getIdentity() {
         return identity;
     }
diff --git a/header/src/main/java/org/zstack/header/storage/snapshot/group/MemorySnapshotValidatorExtensionPoint.java b/header/src/main/java/org/zstack/header/storage/snapshot/group/MemorySnapshotValidatorExtensionPoint.java
index 0d3698457f7..acdc1653390 100644
--- a/header/src/main/java/org/zstack/header/storage/snapshot/group/MemorySnapshotValidatorExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/storage/snapshot/group/MemorySnapshotValidatorExtensionPoint.java
@@ -3,7 +3,16 @@
 import org.zstack.header.errorcode.ErrorCode;
 
 /**
- * Created by LiangHanYu on 2022/6/9 18:30
+ * 内存快照验证扩展点
+ *
+ * <p>触发时机：创建内存快照前，验证 VM 是否符合条件</p>
+ * <p>调用位置：VolumeSnapshotGroupCreator.validate()</p>
+ *
+ * <h3>使用场景：</h3>
+ * <p>各模块通过此扩展点检查 VM 的外部设备或网络引用
+ * 是否与内存快照兼容。</p>
+ *
+ * @since 5.0.0
  */
 public interface MemorySnapshotValidatorExtensionPoint {
     default ErrorCode checkVmWhereMemorySnapshotExistExternalDevices(String VmInstanceUuid) {
diff --git a/header/src/main/java/org/zstack/header/vm/DetachNicExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/DetachNicExtensionPoint.java
index 8d665918a79..6c4f706bfa2 100644
--- a/header/src/main/java/org/zstack/header/vm/DetachNicExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/DetachNicExtensionPoint.java
@@ -3,6 +3,11 @@
 import org.zstack.header.errorcode.ErrorCode;
 import org.zstack.header.network.l3.L3NetworkInventory;
 
+/**
+ * @deprecated This interface has no implementations and should be removed.
+ *             Use {@link org.zstack.header.vm.extensions.VmInstanceDetachNicExtensionPoint} instead.
+ */
+@Deprecated
 public interface DetachNicExtensionPoint {
     ErrorCode validateDetachNicByDriverTypeAndClusterType(L3NetworkInventory l3, VmInstanceInventory vm);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/ResourceConfigMemorySnapshotExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/ResourceConfigMemorySnapshotExtensionPoint.java
index 7f45aa3d96d..dcfef17f851 100644
--- a/header/src/main/java/org/zstack/header/vm/ResourceConfigMemorySnapshotExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/ResourceConfigMemorySnapshotExtensionPoint.java
@@ -2,6 +2,18 @@
 
 import java.util.List;
 
+/**
+ * 内存快照资源配置归档扩展点
+ *
+ * <p>触发时机：创建内存快照时，归档与 VM 相关的资源配置</p>
+ * <p>调用位置：MemorySnapshotManager.archiveResourceConfig()</p>
+ *
+ * <h3>使用场景：</h3>
+ * <p>当 VM 执行内存快照时，各模块通过此扩展点提供需要归档的资源配置，
+ * 以便恢复快照时可以同时恢复相关配置状态。</p>
+ *
+ * @since 5.0.0
+ */
 public interface ResourceConfigMemorySnapshotExtensionPoint {
     List<ArchiveResourceConfigBundle.ResourceConfigBundle> getNeedToArchiveResourceConfig(String resourceUuid);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmAfterAttachL3NetworkExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmAfterAttachL3NetworkExtensionPoint.java
index a651040d121..2e794002b16 100755
--- a/header/src/main/java/org/zstack/header/vm/VmAfterAttachL3NetworkExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmAfterAttachL3NetworkExtensionPoint.java
@@ -3,8 +3,9 @@
 import org.zstack.header.network.l3.L3NetworkInventory;
 
 /**
- * Created by xing5 on 2016/4/18.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmInstanceAttachL3NetworkExtensionPoint#afterAttachL3Network} instead.
  */
+@Deprecated
 public interface VmAfterAttachL3NetworkExtensionPoint {
     void vmAfterAttachL3Network(VmInstanceInventory vm, L3NetworkInventory l3);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmAfterAttachNicExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmAfterAttachNicExtensionPoint.java
index 1e553790aa1..1ed18993d4a 100644
--- a/header/src/main/java/org/zstack/header/vm/VmAfterAttachNicExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmAfterAttachNicExtensionPoint.java
@@ -4,8 +4,9 @@
 import org.zstack.header.core.NoErrorCompletion;
 
 /**
- * Created by LiangHanYu on 2022/4/13 13:24
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmInstanceAttachL3NetworkExtensionPoint#afterAttachL3Network} instead.
  */
+@Deprecated
 public interface VmAfterAttachNicExtensionPoint {
     void afterAttachNic(String nicUuid, VmInstanceInventory vmInstanceInventory, Completion completion);
 
diff --git a/header/src/main/java/org/zstack/header/vm/VmAfterExpungeExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmAfterExpungeExtensionPoint.java
index bf36926e65f..bbb844bfce4 100755
--- a/header/src/main/java/org/zstack/header/vm/VmAfterExpungeExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmAfterExpungeExtensionPoint.java
@@ -2,8 +2,9 @@
 
 
 /**
- * Created by Mei Lei on 8/23/16.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmExpungeExtensionPoint#afterExpunge} instead.
  */
+@Deprecated
 public interface VmAfterExpungeExtensionPoint {
     void vmAfterExpunge(VmInstanceInventory inv);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmBeforeAttachL3NetworkExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmBeforeAttachL3NetworkExtensionPoint.java
index c87a891d2ea..a26a21ec28f 100755
--- a/header/src/main/java/org/zstack/header/vm/VmBeforeAttachL3NetworkExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmBeforeAttachL3NetworkExtensionPoint.java
@@ -3,8 +3,9 @@
 import org.zstack.header.network.l3.L3NetworkInventory;
 
 /**
- * Created by xing5 on 2016/4/18.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmInstanceAttachL3NetworkExtensionPoint#beforeAttachL3Network} instead.
  */
+@Deprecated
 public interface VmBeforeAttachL3NetworkExtensionPoint {
     void vmBeforeAttachL3Network(VmInstanceInventory vm, L3NetworkInventory l3);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmBeforeExpungeExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmBeforeExpungeExtensionPoint.java
index 97aeeea86cf..32b12d03e68 100644
--- a/header/src/main/java/org/zstack/header/vm/VmBeforeExpungeExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmBeforeExpungeExtensionPoint.java
@@ -2,8 +2,9 @@
 
 
 /**
- * Created by Mei Lei on 8/23/16.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmExpungeExtensionPoint#beforeExpunge} instead.
  */
+@Deprecated
 public interface VmBeforeExpungeExtensionPoint {
     void vmBeforeExpunge(VmInstanceInventory inv);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmDetachNicExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmDetachNicExtensionPoint.java
index af11dc0bc66..48ff3ba23ae 100755
--- a/header/src/main/java/org/zstack/header/vm/VmDetachNicExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmDetachNicExtensionPoint.java
@@ -3,8 +3,9 @@
 import org.zstack.header.errorcode.ErrorCode;
 
 /**
- * Created by frank on 7/18/2015.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmInstanceDetachNicExtensionPoint} instead.
  */
+@Deprecated
 public interface VmDetachNicExtensionPoint {
     void preDetachNic(VmNicInventory nic);
 
diff --git a/header/src/main/java/org/zstack/header/vm/VmFailToAttachL3NetworkExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmFailToAttachL3NetworkExtensionPoint.java
index 27f97f23ca8..86769d21d15 100755
--- a/header/src/main/java/org/zstack/header/vm/VmFailToAttachL3NetworkExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmFailToAttachL3NetworkExtensionPoint.java
@@ -4,8 +4,9 @@
 import org.zstack.header.network.l3.L3NetworkInventory;
 
 /**
- * Created by xing5 on 2016/4/18.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmInstanceAttachL3NetworkExtensionPoint#failedToAttachL3Network} instead.
  */
+@Deprecated
 public interface VmFailToAttachL3NetworkExtensionPoint {
     void vmFailToAttachL3Network(VmInstanceInventory vm, L3NetworkInventory l3, ErrorCode error);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmInstanceAttachNicExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmInstanceAttachNicExtensionPoint.java
index 9139f98508f..716b7d6231f 100644
--- a/header/src/main/java/org/zstack/header/vm/VmInstanceAttachNicExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmInstanceAttachNicExtensionPoint.java
@@ -1,5 +1,10 @@
 package org.zstack.header.vm;
 
+/**
+ * @deprecated This interface has no implementations and should be removed.
+ *             Use {@link org.zstack.header.vm.extensions.VmInstanceAttachL3NetworkExtensionPoint} instead.
+ */
+@Deprecated
 public interface VmInstanceAttachNicExtensionPoint {
     void afterAttachNicToVm(VmNicInventory nic);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmInstanceDestroyExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmInstanceDestroyExtensionPoint.java
index 9e285d22fe7..f493758fbc8 100755
--- a/header/src/main/java/org/zstack/header/vm/VmInstanceDestroyExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmInstanceDestroyExtensionPoint.java
@@ -2,6 +2,10 @@
 
 import org.zstack.header.errorcode.ErrorCode;
 
+/**
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmDestroyExtensionPoint} instead.
+ */
+@Deprecated
 public interface VmInstanceDestroyExtensionPoint {
     String preDestroyVm(VmInstanceInventory inv);
 
diff --git a/header/src/main/java/org/zstack/header/vm/VmInstanceSpec.java b/header/src/main/java/org/zstack/header/vm/VmInstanceSpec.java
index 7007c592aea..99ee2173b98 100755
--- a/header/src/main/java/org/zstack/header/vm/VmInstanceSpec.java
+++ b/header/src/main/java/org/zstack/header/vm/VmInstanceSpec.java
@@ -847,7 +847,9 @@ public void setBootMode(String bootMode) {
 
     public long getRootDiskAllocateSize() {
         if (rootDiskOffering == null) {
-            return this.getImageSpec().getInventory().getSize();
+            long virtualSize = this.getImageSpec().getInventory().getSize();
+            long actualSize = this.getImageSpec().getInventory().getActualSize();
+            return Math.max(virtualSize, actualSize);
         }
         return rootDiskOffering.getDiskSize();
     }
diff --git a/header/src/main/java/org/zstack/header/vm/VmInstanceState.java b/header/src/main/java/org/zstack/header/vm/VmInstanceState.java
index 8a755b52fda..49303e23252 100755
--- a/header/src/main/java/org/zstack/header/vm/VmInstanceState.java
+++ b/header/src/main/java/org/zstack/header/vm/VmInstanceState.java
@@ -168,6 +168,7 @@ public enum VmInstanceState {
                 new Transaction(VmInstanceStateEvent.destroyed, VmInstanceState.Destroyed),
                 new Transaction(VmInstanceStateEvent.destroying, VmInstanceState.Destroying),
                 new Transaction(VmInstanceStateEvent.running, VmInstanceState.Running),
+                new Transaction(VmInstanceStateEvent.stopped, VmInstanceState.Stopped),
                 new Transaction(VmInstanceStateEvent.expunging, VmInstanceState.Expunging)
         );
         Destroyed.transactions(
diff --git a/header/src/main/java/org/zstack/header/vm/VmJustAfterDeleteFromDbExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmJustAfterDeleteFromDbExtensionPoint.java
index e4b11666ebc..56c463a2ddc 100644
--- a/header/src/main/java/org/zstack/header/vm/VmJustAfterDeleteFromDbExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmJustAfterDeleteFromDbExtensionPoint.java
@@ -1,8 +1,9 @@
 package org.zstack.header.vm;
 
 /**
- * Created by Qi Le on 2019-08-21
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmDbDeleteContext} with a single-phase extension point instead.
  */
+@Deprecated
 public interface VmJustAfterDeleteFromDbExtensionPoint {
     void vmJustAfterDeleteFromDbExtensionPoint(VmInstanceInventory inv, String accountUuid);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmJustBeforeDeleteFromDbExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmJustBeforeDeleteFromDbExtensionPoint.java
index 4e8337ac805..584ef5ccc55 100755
--- a/header/src/main/java/org/zstack/header/vm/VmJustBeforeDeleteFromDbExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmJustBeforeDeleteFromDbExtensionPoint.java
@@ -1,8 +1,9 @@
 package org.zstack.header.vm;
 
 /**
- * Created by xing5 on 2017/6/26.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmDbDeleteContext} with a single-phase extension point instead.
  */
+@Deprecated
 public interface VmJustBeforeDeleteFromDbExtensionPoint {
     void vmJustBeforeDeleteFromDb(VmInstanceInventory inv);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/VmPreAttachL3NetworkExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/VmPreAttachL3NetworkExtensionPoint.java
index 84240ff0b11..bb40daa67e9 100755
--- a/header/src/main/java/org/zstack/header/vm/VmPreAttachL3NetworkExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/vm/VmPreAttachL3NetworkExtensionPoint.java
@@ -3,8 +3,9 @@
 import org.zstack.header.network.l3.L3NetworkInventory;
 
 /**
- * Created by xing5 on 2016/4/18.
+ * @deprecated Use {@link org.zstack.header.vm.extensions.VmInstanceAttachL3NetworkExtensionPoint#preAttachL3Network} instead.
  */
+@Deprecated
 public interface VmPreAttachL3NetworkExtensionPoint {
     void vmPreAttachL3Network(VmInstanceInventory vm, L3NetworkInventory l3);
 }
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmAttachL3NetworkContext.java b/header/src/main/java/org/zstack/header/vm/extensions/VmAttachL3NetworkContext.java
new file mode 100644
index 00000000000..b874a20347e
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmAttachL3NetworkContext.java
@@ -0,0 +1,67 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.network.l3.L3NetworkInventory;
+import org.zstack.header.vm.VmInstanceInventory;
+import org.zstack.header.vm.VmNicInventory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Context object for VM L3 Network attachment operations.
+ *
+ * <p>This context is passed through all lifecycle phases (pre/before/after/failedTo)
+ * allowing extensions to share state between phases.</p>
+ */
+public class VmAttachL3NetworkContext {
+    private VmInstanceInventory vm;
+    private L3NetworkInventory l3;
+    private VmNicInventory nic;
+    private String accountUuid;
+    private Map<String, Object> additionalData = new HashMap<>();
+
+    public VmInstanceInventory getVm() {
+        return vm;
+    }
+
+    public void setVm(VmInstanceInventory vm) {
+        this.vm = vm;
+    }
+
+    public L3NetworkInventory getL3() {
+        return l3;
+    }
+
+    public void setL3(L3NetworkInventory l3) {
+        this.l3 = l3;
+    }
+
+    public VmNicInventory getNic() {
+        return nic;
+    }
+
+    public void setNic(VmNicInventory nic) {
+        this.nic = nic;
+    }
+
+    public String getAccountUuid() {
+        return accountUuid;
+    }
+
+    public void setAccountUuid(String accountUuid) {
+        this.accountUuid = accountUuid;
+    }
+
+    public Map<String, Object> getAdditionalData() {
+        return additionalData;
+    }
+
+    public void putData(String key, Object value) {
+        additionalData.put(key, value);
+    }
+
+    @SuppressWarnings("unchecked")
+    public <T> T getData(String key) {
+        return (T) additionalData.get(key);
+    }
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmDbDeleteContext.java b/header/src/main/java/org/zstack/header/vm/extensions/VmDbDeleteContext.java
new file mode 100644
index 00000000000..7e484498952
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmDbDeleteContext.java
@@ -0,0 +1,21 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.vm.VmInstanceInventory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class VmDbDeleteContext {
+    private VmInstanceInventory vm;
+    private String accountUuid;
+    private Map<String, Object> additionalData = new HashMap<>();
+
+    public VmInstanceInventory getVm() { return vm; }
+    public void setVm(VmInstanceInventory vm) { this.vm = vm; }
+    public String getAccountUuid() { return accountUuid; }
+    public void setAccountUuid(String accountUuid) { this.accountUuid = accountUuid; }
+    public Map<String, Object> getAdditionalData() { return additionalData; }
+    public void putData(String key, Object value) { additionalData.put(key, value); }
+    @SuppressWarnings("unchecked")
+    public <T> T getData(String key) { return (T) additionalData.get(key); }
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmDestroyContext.java b/header/src/main/java/org/zstack/header/vm/extensions/VmDestroyContext.java
new file mode 100644
index 00000000000..ae5eb770b02
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmDestroyContext.java
@@ -0,0 +1,25 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.errorcode.ErrorCode;
+import org.zstack.header.vm.VmInstanceInventory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class VmDestroyContext {
+    private VmInstanceInventory vm;
+    private String accountUuid;
+    private ErrorCode error;
+    private Map<String, Object> additionalData = new HashMap<>();
+
+    public VmInstanceInventory getVm() { return vm; }
+    public void setVm(VmInstanceInventory vm) { this.vm = vm; }
+    public String getAccountUuid() { return accountUuid; }
+    public void setAccountUuid(String accountUuid) { this.accountUuid = accountUuid; }
+    public ErrorCode getError() { return error; }
+    public void setError(ErrorCode error) { this.error = error; }
+    public Map<String, Object> getAdditionalData() { return additionalData; }
+    public void putData(String key, Object value) { additionalData.put(key, value); }
+    @SuppressWarnings("unchecked")
+    public <T> T getData(String key) { return (T) additionalData.get(key); }
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmDestroyExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/extensions/VmDestroyExtensionPoint.java
new file mode 100644
index 00000000000..d62a782da5b
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmDestroyExtensionPoint.java
@@ -0,0 +1,24 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.core.Completion;
+
+/**
+ * VM Instance Destroy Extension Point (unified)
+ *
+ * <p>Trigger: When user calls DestroyVmInstance API</p>
+ * <p>Call site: VmInstanceBase via VmInstanceExtensionPointEmitter</p>
+ *
+ * <h3>Phase Description:</h3>
+ * <ul>
+ *   <li>preDestroy - Can reject the destroy operation</li>
+ *   <li>beforeDestroy - Preparation before destroy</li>
+ *   <li>afterDestroy - Post-processing after destroy</li>
+ *   <li>failedToDestroy - Cleanup on failure</li>
+ * </ul>
+ */
+public interface VmDestroyExtensionPoint {
+    default String preDestroy(VmDestroyContext ctx) { return null; }
+    default void beforeDestroy(VmDestroyContext ctx) {}
+    default void afterDestroy(VmDestroyContext ctx, Completion completion) { completion.success(); }
+    default void failedToDestroy(VmDestroyContext ctx) {}
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmDetachNicContext.java b/header/src/main/java/org/zstack/header/vm/extensions/VmDetachNicContext.java
new file mode 100644
index 00000000000..bcf0129bc01
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmDetachNicContext.java
@@ -0,0 +1,67 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.errorcode.ErrorCode;
+import org.zstack.header.vm.VmInstanceInventory;
+import org.zstack.header.vm.VmNicInventory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Context object for VM NIC detachment operations.
+ *
+ * <p>This context is passed through all lifecycle phases (pre/before/after/failedTo)
+ * allowing extensions to share state between phases.</p>
+ */
+public class VmDetachNicContext {
+    private VmInstanceInventory vm;
+    private VmNicInventory nic;
+    private String accountUuid;
+    private ErrorCode error;
+    private Map<String, Object> additionalData = new HashMap<>();
+
+    public VmInstanceInventory getVm() {
+        return vm;
+    }
+
+    public void setVm(VmInstanceInventory vm) {
+        this.vm = vm;
+    }
+
+    public VmNicInventory getNic() {
+        return nic;
+    }
+
+    public void setNic(VmNicInventory nic) {
+        this.nic = nic;
+    }
+
+    public String getAccountUuid() {
+        return accountUuid;
+    }
+
+    public void setAccountUuid(String accountUuid) {
+        this.accountUuid = accountUuid;
+    }
+
+    public ErrorCode getError() {
+        return error;
+    }
+
+    public void setError(ErrorCode error) {
+        this.error = error;
+    }
+
+    public Map<String, Object> getAdditionalData() {
+        return additionalData;
+    }
+
+    public void putData(String key, Object value) {
+        additionalData.put(key, value);
+    }
+
+    @SuppressWarnings("unchecked")
+    public <T> T getData(String key) {
+        return (T) additionalData.get(key);
+    }
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmExpungeContext.java b/header/src/main/java/org/zstack/header/vm/extensions/VmExpungeContext.java
new file mode 100644
index 00000000000..e5c7d21f807
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmExpungeContext.java
@@ -0,0 +1,25 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.errorcode.ErrorCode;
+import org.zstack.header.vm.VmInstanceInventory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class VmExpungeContext {
+    private VmInstanceInventory vm;
+    private String accountUuid;
+    private ErrorCode error;
+    private Map<String, Object> additionalData = new HashMap<>();
+
+    public VmInstanceInventory getVm() { return vm; }
+    public void setVm(VmInstanceInventory vm) { this.vm = vm; }
+    public String getAccountUuid() { return accountUuid; }
+    public void setAccountUuid(String accountUuid) { this.accountUuid = accountUuid; }
+    public ErrorCode getError() { return error; }
+    public void setError(ErrorCode error) { this.error = error; }
+    public Map<String, Object> getAdditionalData() { return additionalData; }
+    public void putData(String key, Object value) { additionalData.put(key, value); }
+    @SuppressWarnings("unchecked")
+    public <T> T getData(String key) { return (T) additionalData.get(key); }
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmExpungeExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/extensions/VmExpungeExtensionPoint.java
new file mode 100644
index 00000000000..7b7dd9e582d
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmExpungeExtensionPoint.java
@@ -0,0 +1,24 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.core.Completion;
+
+/**
+ * VM Instance Expunge Extension Point (unified)
+ *
+ * <p>Trigger: When VM is expunged (after destroy + grace period)</p>
+ * <p>Call site: VmInstanceBase.expunge()</p>
+ *
+ * <h3>Phase Description:</h3>
+ * <ul>
+ *   <li>preExpunge - Can reject the expunge operation</li>
+ *   <li>beforeExpunge - Preparation before expunge</li>
+ *   <li>afterExpunge - Post-processing after expunge</li>
+ *   <li>failedToExpunge - Cleanup on failure</li>
+ * </ul>
+ */
+public interface VmExpungeExtensionPoint {
+    default String preExpunge(VmExpungeContext ctx) { return null; }
+    default void beforeExpunge(VmExpungeContext ctx) {}
+    default void afterExpunge(VmExpungeContext ctx, Completion completion) { completion.success(); }
+    default void failedToExpunge(VmExpungeContext ctx) {}
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmInstanceAttachL3NetworkExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/extensions/VmInstanceAttachL3NetworkExtensionPoint.java
new file mode 100644
index 00000000000..fc354fb8717
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmInstanceAttachL3NetworkExtensionPoint.java
@@ -0,0 +1,63 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.core.Completion;
+
+/**
+ * VM L3 Network Attachment Extension Point
+ *
+ * <p>Trigger: When user calls AttachL3NetworkToVm API</p>
+ * <p>Call site: VmInstanceBase.attachL3Network()</p>
+ *
+ * <h3>Phase Description:</h3>
+ * <ul>
+ *   <li>preAttachL3Network - Before NIC creation, can reject the attachment</li>
+ *   <li>beforeAttachL3Network - NIC prepared, about to execute FlowChain</li>
+ *   <li>afterAttachL3Network - Attachment complete, network services configured</li>
+ *   <li>failedToAttachL3Network - Attachment failed, cleanup resources</li>
+ * </ul>
+ *
+ * <h3>Method Signatures:</h3>
+ * <ul>
+ *   <li>pre: Returns error message String, null means pass</li>
+ *   <li>before: Synchronous void, for preparation</li>
+ *   <li>after: Asynchronous with Completion, for post-processing</li>
+ *   <li>failedTo: Synchronous void, for cleanup</li>
+ * </ul>
+ */
+public interface VmInstanceAttachL3NetworkExtensionPoint {
+    /**
+     * Called before NIC creation. Can reject the attachment by returning an error message.
+     *
+     * @param ctx the attachment context
+     * @return error message if rejected, null if passed
+     */
+    default String preAttachL3Network(VmAttachL3NetworkContext ctx) {
+        return null;
+    }
+
+    /**
+     * Called after NIC is prepared, before executing the attachment FlowChain.
+     *
+     * @param ctx the attachment context
+     */
+    default void beforeAttachL3Network(VmAttachL3NetworkContext ctx) {
+    }
+
+    /**
+     * Called after attachment is complete. Asynchronous for post-processing.
+     *
+     * @param ctx the attachment context (nic field is populated)
+     * @param completion callback to signal completion
+     */
+    default void afterAttachL3Network(VmAttachL3NetworkContext ctx, Completion completion) {
+        completion.success();
+    }
+
+    /**
+     * Called when attachment fails. Cleanup any resources allocated in previous phases.
+     *
+     * @param ctx the attachment context
+     */
+    default void failedToAttachL3Network(VmAttachL3NetworkContext ctx) {
+    }
+}
diff --git a/header/src/main/java/org/zstack/header/vm/extensions/VmInstanceDetachNicExtensionPoint.java b/header/src/main/java/org/zstack/header/vm/extensions/VmInstanceDetachNicExtensionPoint.java
new file mode 100644
index 00000000000..57aea614821
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/vm/extensions/VmInstanceDetachNicExtensionPoint.java
@@ -0,0 +1,63 @@
+package org.zstack.header.vm.extensions;
+
+import org.zstack.header.core.Completion;
+
+/**
+ * VM NIC Detachment Extension Point
+ *
+ * <p>Trigger: When user calls DetachL3NetworkFromVm API</p>
+ * <p>Call site: VmInstanceBase.detachNic()</p>
+ *
+ * <h3>Phase Description:</h3>
+ * <ul>
+ *   <li>preDetachNic - Before detachment, can reject the operation</li>
+ *   <li>beforeDetachNic - About to execute detachment FlowChain</li>
+ *   <li>afterDetachNic - Detachment complete, NIC removed</li>
+ *   <li>failedToDetachNic - Detachment failed, restore state</li>
+ * </ul>
+ *
+ * <h3>Method Signatures:</h3>
+ * <ul>
+ *   <li>pre: Returns error message String, null means pass</li>
+ *   <li>before: Synchronous void, for preparation</li>
+ *   <li>after: Asynchronous with Completion, for post-processing</li>
+ *   <li>failedTo: Synchronous void, for cleanup</li>
+ * </ul>
+ */
+public interface VmInstanceDetachNicExtensionPoint {
+    /**
+     * Called before NIC detachment. Can reject the operation by returning an error message.
+     *
+     * @param ctx the detachment context
+     * @return error message if rejected, null if passed
+     */
+    default String preDetachNic(VmDetachNicContext ctx) {
+        return null;
+    }
+
+    /**
+     * Called before executing the detachment FlowChain.
+     *
+     * @param ctx the detachment context
+     */
+    default void beforeDetachNic(VmDetachNicContext ctx) {
+    }
+
+    /**
+     * Called after detachment is complete. Asynchronous for post-processing.
+     *
+     * @param ctx the detachment context
+     * @param completion callback to signal completion
+     */
+    default void afterDetachNic(VmDetachNicContext ctx, Completion completion) {
+        completion.success();
+    }
+
+    /**
+     * Called when detachment fails. Restore any state changed in previous phases.
+     *
+     * @param ctx the detachment context (error field is populated)
+     */
+    default void failedToDetachNic(VmDetachNicContext ctx) {
+    }
+}
diff --git a/header/src/main/java/org/zstack/header/volume/VolumeBeforeExpungeExtensionPoint.java b/header/src/main/java/org/zstack/header/volume/VolumeBeforeExpungeExtensionPoint.java
index 673c7cbf9bd..ba4594264ac 100755
--- a/header/src/main/java/org/zstack/header/volume/VolumeBeforeExpungeExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/volume/VolumeBeforeExpungeExtensionPoint.java
@@ -4,8 +4,9 @@
 import org.zstack.header.core.NoErrorCompletion;
 
 /**
- * Created by xing5 on 2016/5/3.
+ * @deprecated Use {@link org.zstack.header.volume.extensions.VolumeExpungeExtPoint} instead.
  */
+@Deprecated
 public interface VolumeBeforeExpungeExtensionPoint {
     void volumePreExpunge(VolumeInventory volume);
     void volumeBeforeExpunge(VolumeInventory volume, NoErrorCompletion completion);
diff --git a/header/src/main/java/org/zstack/header/volume/VolumeDeletionExtensionPoint.java b/header/src/main/java/org/zstack/header/volume/VolumeDeletionExtensionPoint.java
index 8985e000c3f..3b40566e230 100755
--- a/header/src/main/java/org/zstack/header/volume/VolumeDeletionExtensionPoint.java
+++ b/header/src/main/java/org/zstack/header/volume/VolumeDeletionExtensionPoint.java
@@ -4,8 +4,9 @@
 import org.zstack.header.errorcode.ErrorCode;
 
 /**
- * Created by frank on 6/18/2015.
+ * @deprecated Use {@link org.zstack.header.volume.extensions.VolumeDeletionExtPoint} instead.
  */
+@Deprecated
 public interface VolumeDeletionExtensionPoint {
     void preDeleteVolume(VolumeInventory volume);
 
diff --git a/header/src/main/java/org/zstack/header/volume/extensions/VolumeDeleteContext.java b/header/src/main/java/org/zstack/header/volume/extensions/VolumeDeleteContext.java
new file mode 100644
index 00000000000..7c3efdec410
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/volume/extensions/VolumeDeleteContext.java
@@ -0,0 +1,25 @@
+package org.zstack.header.volume.extensions;
+
+import org.zstack.header.errorcode.ErrorCode;
+import org.zstack.header.volume.VolumeInventory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class VolumeDeleteContext {
+    private VolumeInventory volume;
+    private String accountUuid;
+    private ErrorCode error;
+    private Map<String, Object> additionalData = new HashMap<>();
+
+    public VolumeInventory getVolume() { return volume; }
+    public void setVolume(VolumeInventory volume) { this.volume = volume; }
+    public String getAccountUuid() { return accountUuid; }
+    public void setAccountUuid(String accountUuid) { this.accountUuid = accountUuid; }
+    public ErrorCode getError() { return error; }
+    public void setError(ErrorCode error) { this.error = error; }
+    public Map<String, Object> getAdditionalData() { return additionalData; }
+    public void putData(String key, Object value) { additionalData.put(key, value); }
+    @SuppressWarnings("unchecked")
+    public <T> T getData(String key) { return (T) additionalData.get(key); }
+}
diff --git a/header/src/main/java/org/zstack/header/volume/extensions/VolumeDeletionExtPoint.java b/header/src/main/java/org/zstack/header/volume/extensions/VolumeDeletionExtPoint.java
new file mode 100644
index 00000000000..f365747c6a8
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/volume/extensions/VolumeDeletionExtPoint.java
@@ -0,0 +1,24 @@
+package org.zstack.header.volume.extensions;
+
+import org.zstack.header.core.Completion;
+
+/**
+ * Volume Deletion Extension Point (unified)
+ *
+ * <p>Trigger: When user calls DeleteDataVolume API</p>
+ * <p>Call site: VolumeBase.delete()</p>
+ *
+ * <h3>Phase Description:</h3>
+ * <ul>
+ *   <li>preDelete - Can reject the deletion</li>
+ *   <li>beforeDelete - Preparation before deletion</li>
+ *   <li>afterDelete - Post-processing after deletion</li>
+ *   <li>failedToDelete - Cleanup on failure</li>
+ * </ul>
+ */
+public interface VolumeDeletionExtPoint {
+    default String preDelete(VolumeDeleteContext ctx) { return null; }
+    default void beforeDelete(VolumeDeleteContext ctx) {}
+    default void afterDelete(VolumeDeleteContext ctx, Completion completion) { completion.success(); }
+    default void failedToDelete(VolumeDeleteContext ctx) {}
+}
diff --git a/header/src/main/java/org/zstack/header/volume/extensions/VolumeExpungeContext.java b/header/src/main/java/org/zstack/header/volume/extensions/VolumeExpungeContext.java
new file mode 100644
index 00000000000..6488058d348
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/volume/extensions/VolumeExpungeContext.java
@@ -0,0 +1,25 @@
+package org.zstack.header.volume.extensions;
+
+import org.zstack.header.errorcode.ErrorCode;
+import org.zstack.header.volume.VolumeInventory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class VolumeExpungeContext {
+    private VolumeInventory volume;
+    private String accountUuid;
+    private ErrorCode error;
+    private Map<String, Object> additionalData = new HashMap<>();
+
+    public VolumeInventory getVolume() { return volume; }
+    public void setVolume(VolumeInventory volume) { this.volume = volume; }
+    public String getAccountUuid() { return accountUuid; }
+    public void setAccountUuid(String accountUuid) { this.accountUuid = accountUuid; }
+    public ErrorCode getError() { return error; }
+    public void setError(ErrorCode error) { this.error = error; }
+    public Map<String, Object> getAdditionalData() { return additionalData; }
+    public void putData(String key, Object value) { additionalData.put(key, value); }
+    @SuppressWarnings("unchecked")
+    public <T> T getData(String key) { return (T) additionalData.get(key); }
+}
diff --git a/header/src/main/java/org/zstack/header/volume/extensions/VolumeExpungeExtPoint.java b/header/src/main/java/org/zstack/header/volume/extensions/VolumeExpungeExtPoint.java
new file mode 100644
index 00000000000..b51dd4c5c15
--- /dev/null
+++ b/header/src/main/java/org/zstack/header/volume/extensions/VolumeExpungeExtPoint.java
@@ -0,0 +1,24 @@
+package org.zstack.header.volume.extensions;
+
+import org.zstack.header.core.Completion;
+
+/**
+ * Volume Expunge Extension Point (unified)
+ *
+ * <p>Trigger: When volume is expunged (after delete + grace period)</p>
+ * <p>Call site: VolumeBase.expunge()</p>
+ *
+ * <h3>Phase Description:</h3>
+ * <ul>
+ *   <li>preExpunge - Can reject the expunge (or skip it)</li>
+ *   <li>beforeExpunge - Preparation before expunge</li>
+ *   <li>afterExpunge - Post-processing after expunge</li>
+ *   <li>failedToExpunge - Cleanup on failure</li>
+ * </ul>
+ */
+public interface VolumeExpungeExtPoint {
+    default String preExpunge(VolumeExpungeContext ctx) { return null; }
+    default void beforeExpunge(VolumeExpungeContext ctx) {}
+    default void afterExpunge(VolumeExpungeContext ctx, Completion completion) { completion.success(); }
+    default void failedToExpunge(VolumeExpungeContext ctx) {}
+}
diff --git a/network/src/main/java/org/zstack/network/l3/L3BasicNetwork.java b/network/src/main/java/org/zstack/network/l3/L3BasicNetwork.java
index 5536a5fc487..b1b0b92d497 100755
--- a/network/src/main/java/org/zstack/network/l3/L3BasicNetwork.java
+++ b/network/src/main/java/org/zstack/network/l3/L3BasicNetwork.java
@@ -1075,6 +1075,13 @@ private void handle(APIGetFreeIpMsg msg) {
             }
             limit -= freeIpInventorys.size();
         }
+
+        Set<ReservedIpRangeVO> reservedIpRanges = self.getReservedIpRanges();
+        if (reservedIpRanges != null && !reservedIpRanges.isEmpty()) {
+            freeIpInventorys.removeIf(freeIp -> reservedIpRanges.stream().anyMatch(
+                    r -> NetworkUtils.isInRange(freeIp.getIp(), r.getStartIp(), r.getEndIp())));
+        }
+
         reply.setInventories(freeIpInventorys);
 
         bus.reply(msg, reply);
diff --git a/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/CephPrimaryStorageBase.java b/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/CephPrimaryStorageBase.java
index d80b40a1d6a..8b387306683 100755
--- a/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/CephPrimaryStorageBase.java
+++ b/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/CephPrimaryStorageBase.java
@@ -5446,7 +5446,7 @@ private void deleteSnapshotOnPrimaryStorage(final DeleteSnapshotOnPrimaryStorage
         httpCall(DELETE_SNAPSHOT_PATH, cmd, DeleteSnapshotRsp.class, new ReturnValueCompletion<DeleteSnapshotRsp>(msg) {
             @Override
             public void success(DeleteSnapshotRsp returnValue) {
-                osdHelper.releaseAvailableCapacity(msg.getSnapshot().getPrimaryStorageInstallPath(), msg.getSnapshot().getSize());
+                osdHelper.releaseAvailableCapWithRatio(msg.getSnapshot().getPrimaryStorageInstallPath(), msg.getSnapshot().getSize());
                 bus.reply(msg, reply);
                 completion.done();
             }
diff --git a/plugin/loadBalancer/src/main/java/org/zstack/network/service/lb/LoadBalancerApiInterceptor.java b/plugin/loadBalancer/src/main/java/org/zstack/network/service/lb/LoadBalancerApiInterceptor.java
index 97b88c919c2..0d9946d5320 100755
--- a/plugin/loadBalancer/src/main/java/org/zstack/network/service/lb/LoadBalancerApiInterceptor.java
+++ b/plugin/loadBalancer/src/main/java/org/zstack/network/service/lb/LoadBalancerApiInterceptor.java
@@ -39,6 +39,7 @@
 import org.zstack.network.service.vip.VipVO_;
 import org.zstack.tag.PatternedSystemTag;
 import org.zstack.tag.TagManager;
+import org.zstack.core.upgrade.UpgradeGlobalConfig;
 import org.zstack.utils.*;
 import org.zstack.utils.function.ForEachFunction;
 import org.zstack.utils.logging.CLogger;
@@ -152,10 +153,22 @@ public APIMessage intercept(APIMessage msg) throws ApiMessageInterceptionExcepti
             validate((APIGetCandidateVmNicsForLoadBalancerServerGroupMsg)msg);
         } else if (msg instanceof APIChangeLoadBalancerBackendServerMsg) {
             validate((APIChangeLoadBalancerBackendServerMsg)msg);
+        } else if (msg instanceof APIDeleteLoadBalancerMsg) {
+            validate((APIDeleteLoadBalancerMsg) msg);
         }
         return msg;
     }
 
+    private void validate(APIDeleteLoadBalancerMsg msg) {
+        if (UpgradeGlobalConfig.GRAYSCALE_UPGRADE.value(Boolean.class)) {
+            LoadBalancerVO lb = dbf.findByUuid(msg.getUuid(), LoadBalancerVO.class);
+            if (lb != null && lb.getType() == LoadBalancerType.SLB) {
+                throw new ApiMessageInterceptionException(argerr(
+                        "cannot delete the standalone load balancer[uuid:%s] during grayscale upgrade", msg.getUuid()));
+            }
+        }
+    }
+
     private void validate(APIDeleteAccessControlListMsg msg) {
         /*List<String> refs = Q.New(LoadBalancerListenerACLRefVO.class).select(LoadBalancerListenerACLRefVO_.listenerUuid)
                              .eq(LoadBalancerListenerACLRefVO_.aclUuid, msg.getUuid()).isNull(LoadBalancerListenerACLRefVO_.serverGroupUuid).listValues();
diff --git a/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java b/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java
index db06239acb3..276ab367ba1 100644
--- a/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java
+++ b/plugin/zbs/src/main/java/org/zstack/storage/zbs/ZbsStorageController.java
@@ -179,7 +179,10 @@ public List<ActiveVolumeClient> getActiveClients(String installPath, String prot
         if (VolumeProtocol.CBD.toString().equals(protocol)) {
             GetVolumeClientsCmd cmd = new GetVolumeClientsCmd();
             cmd.setPath(installPath);
-            GetVolumeClientsRsp rsp = syncHttpCall(GET_VOLUME_CLIENTS_PATH, cmd, GetVolumeClientsRsp.class);
+            GetVolumeClientsRsp rsp = new HttpCaller<>(GET_VOLUME_CLIENTS_PATH, cmd, GetVolumeClientsRsp.class,
+                    null, TimeUnit.SECONDS, 30, true)
+                    .setTryNext(true)
+                    .syncCall();
             List<ActiveVolumeClient> clients = new ArrayList<>();
 
             if (!rsp.isSuccess()) {
@@ -1411,6 +1414,11 @@ public class HttpCaller<T extends AgentResponse> {
 
         private boolean tryNext = false;
 
+        HttpCaller<T> setTryNext(boolean tryNext) {
+            this.tryNext = tryNext;
+            return this;
+        }
+
         public HttpCaller(String path, AgentCommand cmd, Class<T> retClass, ReturnValueCompletion<T> callback) {
             this(path, cmd, retClass, callback, null, 0, false);
         }
diff --git a/portal/src/main/java/org/zstack/portal/managementnode/ManagementNodeManagerImpl.java b/portal/src/main/java/org/zstack/portal/managementnode/ManagementNodeManagerImpl.java
index a945ab77274..4ece718ff52 100755
--- a/portal/src/main/java/org/zstack/portal/managementnode/ManagementNodeManagerImpl.java
+++ b/portal/src/main/java/org/zstack/portal/managementnode/ManagementNodeManagerImpl.java
@@ -74,6 +74,7 @@
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -107,6 +108,15 @@ public class ManagementNodeManagerImpl extends AbstractService implements Manage
     // A dictionary (nodeId -> ManagementNodeInventory) of joined management Node
     final private Map<String, ManagementNodeInventory> joinedManagementNodes = new ConcurrentHashMap<>();
 
+    // Lock to serialize lifecycle events from heartbeat reconciliation and canonical event callbacks,
+    // preventing race conditions where a nodeJoin event is immediately followed by a stale nodeLeft
+    // from the heartbeat thread, or vice versa. See ZSTAC-77711.
+    private final Object lifecycleLock = new Object();
+
+    // Track nodes found in hash ring but missing from DB. Only call nodeLeft after a node
+    // is missing for two consecutive heartbeat cycles, to avoid removing nodes that just joined.
+    private final Set<String> suspectedMissingFromDb = new HashSet<>();
+
     private static int NODE_STARTING = 0;
     private static int NODE_RUNNING = 1;
     private static int NODE_FAILED = -1;
@@ -368,12 +378,16 @@ protected void run(Map tokens, Object data) {
 
             ManagementNodeLifeCycleData d = (ManagementNodeLifeCycleData) data;
 
-            if (LifeCycle.NodeJoin.toString().equals(d.getLifeCycle())) {
-                nodeLifeCycle.nodeJoin(d.getInventory());
-            } else if (LifeCycle.NodeLeft.toString().equals(d.getLifeCycle())) {
-                nodeLifeCycle.nodeLeft(d.getInventory());
-            } else {
-                throw new CloudRuntimeException(String.format("unknown lifecycle[%s]", d.getLifeCycle()));
+            synchronized (lifecycleLock) {
+                if (LifeCycle.NodeJoin.toString().equals(d.getLifeCycle())) {
+                    // Clear from suspected set since the node is confirmed alive
+                    suspectedMissingFromDb.remove(d.getInventory().getUuid());
+                    nodeLifeCycle.nodeJoin(d.getInventory());
+                } else if (LifeCycle.NodeLeft.toString().equals(d.getLifeCycle())) {
+                    nodeLifeCycle.nodeLeft(d.getInventory());
+                } else {
+                    throw new CloudRuntimeException(String.format("unknown lifecycle[%s]", d.getLifeCycle()));
+                }
             }
         }
     };
@@ -860,34 +874,55 @@ private void checkAllNodesHealth() {
 
                 Set<String> nodeUuidsInDb = nodesInDb.stream().map(ManagementNodeVO::getUuid).collect(Collectors.toSet());
 
-                // When a node is dying, we may not receive the the dead notification because the message bus may be also dead
-                // at that moment. By checking if the node UUID is still in our hash ring, we know what nodes should be kicked out
-                destinationMaker.getManagementNodesInHashRing().forEach(nodeUuid -> {
-                    if (!nodeUuidsInDb.contains(nodeUuid)) {
-                        logger.warn(String.format("found that a management node[uuid:%s] had no heartbeat in database but still in our hash ring," +
-                                "notify that it's dead", nodeUuid));
-                        ManagementNodeInventory inv = new ManagementNodeInventory();
-                        inv.setUuid(nodeUuid);
-                        inv.setHostName(destinationMaker.getNodeInfo(nodeUuid).getNodeIP());
-
-                        nodeLifeCycle.nodeLeft(inv);
-                    }
-                });
-
-                // check if any node missing in our hash ring
-                nodesInDb.forEach(n -> {
-                    if (n.getUuid().equals(node().getUuid()) || suspects.contains(n)) {
-                        return;
-                    }
-
-                    new Runnable() {
-                        @Override
-                        @AsyncThread
-                        public void run() {
-                            nodeLifeCycle.nodeJoin(ManagementNodeInventory.valueOf(n));
+                // Reconcile hash ring with DB under lifecycleLock to prevent race with
+                // canonical event callbacks (nodeJoin/nodeLeft). See ZSTAC-77711.
+                synchronized (lifecycleLock) {
+                    // When a node is dying, we may not receive the dead notification because the message bus may be also dead
+                    // at that moment. By checking if the node UUID is still in our hash ring, we know what nodes should be kicked out.
+                    // Use two-round confirmation: first round marks as suspected, second round actually removes.
+                    Set<String> currentSuspected = new HashSet<>();
+                    destinationMaker.getManagementNodesInHashRing().forEach(nodeUuid -> {
+                        if (!nodeUuidsInDb.contains(nodeUuid)) {
+                            if (suspectedMissingFromDb.contains(nodeUuid)) {
+                                // Second consecutive detection — confirmed missing, remove from hash ring
+                                logger.warn(String.format("management node[uuid:%s] confirmed missing from database for two consecutive" +
+                                        " heartbeat cycles, removing from hash ring", nodeUuid));
+                                ManagementNodeInventory inv = new ManagementNodeInventory();
+                                inv.setUuid(nodeUuid);
+                                try {
+                                    inv.setHostName(destinationMaker.getNodeInfo(nodeUuid).getNodeIP());
+                                } catch (Exception e) {
+                                    logger.warn(String.format("cannot get node info for node[uuid:%s], use empty hostname", nodeUuid));
+                                }
+
+                                nodeLifeCycle.nodeLeft(inv);
+                            } else {
+                                // First detection — mark as suspected, defer removal to next cycle
+                                logger.warn(String.format("management node[uuid:%s] not found in database but still in hash ring," +
+                                        " marking as suspected (will remove on next heartbeat if still missing)", nodeUuid));
+                                currentSuspected.add(nodeUuid);
+                            }
                         }
-                    }.run();
-                });
+                    });
+                    // Update suspected set: only keep nodes that are newly suspected this round
+                    suspectedMissingFromDb.clear();
+                    suspectedMissingFromDb.addAll(currentSuspected);
+
+                    // check if any node missing in our hash ring
+                    nodesInDb.forEach(n -> {
+                        if (n.getUuid().equals(node().getUuid()) || suspects.contains(n)) {
+                            return;
+                        }
+
+                        new Runnable() {
+                            @Override
+                            @AsyncThread
+                            public void run() {
+                                nodeLifeCycle.nodeJoin(ManagementNodeInventory.valueOf(n));
+                            }
+                        }.run();
+                    });
+                }
             }
 
             @Override
diff --git a/utils/src/main/java/org/zstack/utils/clouderrorcode/CloudOperationsErrorCode.java b/utils/src/main/java/org/zstack/utils/clouderrorcode/CloudOperationsErrorCode.java
index a0f09d4f1e9..a550fb7d673 100644
--- a/utils/src/main/java/org/zstack/utils/clouderrorcode/CloudOperationsErrorCode.java
+++ b/utils/src/main/java/org/zstack/utils/clouderrorcode/CloudOperationsErrorCode.java
@@ -6274,6 +6274,8 @@ public class CloudOperationsErrorCode {
 
     public static final String ORG_ZSTACK_STORAGE_BACKUP_10133 = "ORG_ZSTACK_STORAGE_BACKUP_10133";
 
+    public static final String ORG_ZSTACK_STORAGE_BACKUP_CANCEL_TIMEOUT = "ORG_ZSTACK_STORAGE_BACKUP_CANCEL_TIMEOUT";
+
     public static final String ORG_ZSTACK_COMPUTE_10000 = "ORG_ZSTACK_COMPUTE_10000";
 
     public static final String ORG_ZSTACK_COMPUTE_10001 = "ORG_ZSTACK_COMPUTE_10001";