Clustered shared volumes go offline or the Cluster service stops during VM backup on a Windows Server 2012 Hyper-V host server

Vrijedi za: Hyper-V Server 2012Hyper-V Server 2012Windows Server 2012 Datacenter

Important The hotfix that corresponds to KB 2908415 has been included with the hotfix KB 2878635, which contains all fixes that were previously included in KB 2908415.


Consider the following scenario:
  • You have a Windows Server 2012 Hyper-V host server.
  • You have the server in a cluster environment, and you use cluster shared volumes.
  • You try to back up a virtual machine (VM).

In this scenario, you may find that the cluster shared volumes go offline, and resource failover occurs on the other cluster nodes. Then, other VMs also go offline, or the Cluster service stops.


This problem occurs when there are many snapshots in the VM. This causes the Plug and Play (PnP) functionality on the host to be overwhelmed, and other critical cluster activity cannot finish.

Known issue

After you apply this hotfix and update the integration service in virtual machines, any snapshots that are older than 30 days and additional snapshots that are more than six are deleted in virtual machines. Additionally, event ID 16 that resembles the following is logged in the Application log:


The function can be disabled by setting the following registry in virtual machines. However, the issue that is described in this article might occur after that.
Registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Virtualization\VssRequestor
DWORD: SnapshotAreaRemoval
Value: (Disable)


Hotfix information

A supported hotfix is available from Microsoft Support. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, go to the following Microsoft website: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.


To apply this hotfix, you must have Service Pack 1 for Windows 7 or Windows Server 2008 R2 installed.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

The hotfix that corresponds to KB 2908415 has been included with the hotfix KB 2878635, which contains all fixes that were previously included in KB 2908415. You should use the hotfix KB 2878635 to fix the issues described in KB 2908415. For more information, click the following article number to view the article in the Microsoft Knowledge Base: 
2878635 Update is available that improves the resiliency of the cloud service provider in Windows Server 2012: December 2013


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


See the terminology Microsoft uses to describe software updates for more information.