Virtual machines that host on Windows Server 2012 R2 may crash or restart unexpectedly

Applies to: Windows Server 2012 R2 DatacenterWindows Server 2012 R2 StandardWindows Server 2012 R2 Essentials More

This article describes an issue in which virtual machines that host on Windows Server 2012 R2 may crash or restart unexpectedly because of an issue in Cluster Shared Volume File System (CSVFS). A hotfix is available to resolve this issue. Before you install this hotfix, see the Prerequisites section.


This issue occurs when one of the following conditions is true:
  • You have a Scale-Out File Server (SOFS) cluster that has .vhd or .vhdx files hosted on it.
  • You have a Hyper-V cluster that has .vhd or .vhdx files hosted on the local cluster shared volumes (CSV).
You may find events in the System event log that indicates that the Resource Hosting Subsystem (Rhs.exe) process experienced a deadlock.


To resolve this issue, install the hotfix on the storage nodes where CSVFS is running. This hotfix has to be applied to all nodes of a failover cluster that is hosting the .vhd or .vhdx files for the problem to be resolved.

Hotfix information

Important If you install a language pack after you install this hotfix, you must reinstall this hotfix. Therefore, we recommend that you install any language packs that you need before you install this hotfix. For more information, see Add language packs to Windows.

A supported hotfix is available from Microsoft. 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 this specific problem.

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, submit a request to 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, visit 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 update 2919355 installed in Windows Server 2012 R2.

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You may have to restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

Additional file information

Additional file information for Windows Server 2012 R2
Additional files for all supported x64-based versions of Windows Server 2012 R2
File propertyValue
File nameAmd64_ecd6038069d1c7dd1d0cbbd4b7d6ed2b_31bf3856ad364e35_6.3.9600.17891_none_b3972bfa62274580.manifest
File versionNot applicable
File size718
Date (UTC)29-May-2015
Time (UTC)09:02
PlatformNot applicable
File nameAmd64_microsoft-windows-f..rcluster-csvfs-core_31bf3856ad364e35_6.3.9600.17891_none_c6e75836336faa06.manifest
File versionNot applicable
File size3,087
Date (UTC)29-May-2015
Time (UTC)04:16
PlatformNot applicable


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


See the terminology that Microsoft uses to describe software updates.