I/O failures occur when you create a snapshot for a large volume in Windows Server 2012 or Windows Server 2008 R2 SP1

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

Symptoms


When you create a snapshot for a large volume on a Windows Server 2012-based or Windows Server 2008 R2 Service Pack 1 (SP1)-based computer, snapshot creation takes a long time to finish. Additionally, some I/O failures occur during snapshot creation.

For example, when you create a snapshot for a volume that is larger than 50 terabytes (TB), it takes a long time to complete the snapshot creation. Additionally, you experience mouse or keyboard input problems and network connection loss during the snapshot creation.

Note If this issue occurs on a Windows Server 2012-based failover cluster, cluster heartbeat failure occurs. Therefore, the cluster disk resource goes offline, and then the snapshot creation fails.

Cause


This issue occurs because the Volsnap.sys driver spends too much time marking available space on the volume when holding a spinlock.

Resolution


This hotfix is also available at Microsoft Update Catalog.

Hotfix information

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 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, 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.

Prerequisites

To apply this hotfix, you must be running Windows Server 2012 or Windows Server 2008 R2 SP1.

For more information about how to obtain a Windows 7 or Windows Server 2008 R2 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

976932 Information about Service Pack 1 for Windows 7 and for Windows Server 2008 R2

Registry information

To apply this hotfix, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

Status


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

More Information


For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates