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A Hyper-V update rollup is available for Windows Server 2008 R2

View products that this article applies to.


This article (KB975354) provides an update rollup for various Hyper-V issues in Windows Server 2008 R2 and on Windows 7-based computers that have the Hyper-V role installed. These issues occur when you back up or restore Hyper-V virtual machines (VMs). For detailed information, see the “Symptoms,” “Cause,” and “Resolution” sections of this article.

To download the fix for these issues, click the View and request hotfix downloads link that is located on the upper-left of the screen.

For details about the most recent Hyper-V updates, including all the updates that were released since this update rollup, visit the following Microsoft website:


Issue 1

Consider the following scenario:
  • Some Internet SCSI (iSCSI) connections are created in a virtual machine that is running Windows Server 2003.
  • You back up this virtual machine (VM) on the VM host server.
In this scenario, a 0x800423f4 error code occurs when you back up the virtual machine. Additionally, the following event is logged in the Hyper-V Virtual Machine Management Service event log:

Issue 2

Consider the following scenario:
  • Cluster shared volumes are enabled on a failover cluster for Hyper-V.
  • Some virtual machines (VMs) are saved on the same volume. However, the VMs are running on different nodes.
  • These VMs are backed up in parallel.
In this scenario, the VM backup operation fails.

Issue 3

Consider the following scenario:
  • A virtual machine (VM) is being backed up on a server that is running Hyper-V.
  • At the same time, an application backup operation is being performed in the same VM.
In this scenario, some data is truncated from the application backup in the VM. Therefore, this behavior causes data loss.

Issue 4

Consider the following scenario:
  • A virtual machine (VM) that has some snapshots is backed up on a server that is running Hyper-V.
  • The VM is restored to another location.
In this scenario, the restore operation fails and the VM may be corrupted.

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Issue 1

When a virtual machine (VM) is being backed up, the VSS writer of the server that is running Hyper-V makes a call to the guest VM to check whether any iSCSI connections exist. This call has a default time-out of 60 seconds. If this call does not return within the time limitation, the VSS writer of the server that is running Hyper-V incorrectly assumes that there is no iSCSI connection. Therefore, the backup operation fails.

Issue 2

When the virtual machines (VMs) on different nodes are backed up in parallel, every node waits to become the cluster shared volume owner to create the snapshots. However, the Cluster service moves the volume owner from one node to another node immediately after a snapshot is created without waiting for post-snapshot tasks to be completed. If another node requests the same shared volume for a backup operation before the post-snapshot tasks are completed, the Cluster service changes the volume to another node. Therefore, the VSS writer that is in the previous node cannot find the cluster shared volume locally when it performs post-snapshot tasks. This behavior causes the VM backup operation to fail.

Issue 3

The application backup operation in the virtual machine (VM) is incorrectly affected by the VM backup operation on the server that is running Hyper-V.

Issue 4

The snapshot files are not restored successfully when you restore the virtual machine (VM).

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Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
Note You may still experience issue 3 after you install this hotfix. You can apply the following registry entry in a virtual machine to fix issue 3 for that virtual machine:
Location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Virtualization\VssRequestor

Name: BackupType


Value: 0 or 1
If this registry entry is created and its value is set to 1, application backup will not be affected by the virtual machine backup operation on the server that is running Hyper-V. If this registry entry does not exist, or if its value is 0, issue 3 occurs.

Hotfix information

After you install this hotfix on the Hyper-V server, you must update the Integration Components in the virtual machines. To do this, open the Virtual Machine Connection for the virtual machine in Hyper-V Manager, and then select the Insert Integration Services Setup Disk option on the Action menu.

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 Web site: 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, the computer must be running one of the following operating systems:
  • Windows Server 2008 R2
  • Windows 7
  • This update contains fixes for both VSS and Hyper-V. The Hyper-V update only applies to x64-based versions of Windows Server 2008 R2.
  • After you install this rollup, Hyper-V will only use the VSS system provider inside the virtual machine when performing a host-level backup.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfix.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
Windows Server 2008 R2 and Windows 7 file information note

The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are
listed separately. MUM and MANIFEST files, and the associated security catalog (.cat) files, are critical to maintaining the state of the updated component. The security catalog files (attributes not listed) are signed with a Microsoft digital signature.
For all supported x86-based versions of Windows 7

File nameFile versionFile sizeDateTimePlatform
75dfb225-e2e4-4d39-9ac9-ffaff65ddf06.xmlNot Applicable2,77610-Jun-200921:47Not Applicable
For all supported x64-based versions of Windows Server 2008 R2 and of Windows7

File nameFile versionFile sizeDateTimePlatform
Windows5.x-hypervintegrationservices-x64.msiNot Applicable1,456,64006-Oct-200906:46Not Applicable
Windows6.0-hypervintegrationservices-x64.cabNot Applicable448,50706-Oct-200907:15Not Applicable
Windows6.1-hypervintegrationservices-x64.cabNot Applicable448,01906-Oct-200907:27Not Applicable
75dfb225-e2e4-4d39-9ac9-ffaff65ddf06.xmlNot Applicable2,77610-Jun-200921:08Not Applicable
For all supported Itanium-based versions of Windows Server 2008 R2

File nameFile versionFile sizeDateTimePlatformService branch
75dfb225-e2e4-4d39-9ac9-ffaff65ddf06.xmlNot Applicable2,77610-Jun-200921:14Not ApplicableNot Applicable
Eventcls.dll6.1.7600.1638531,23214-Jul-200901:46IA-64Not Applicable
Vssapi.dll6.1.7600.205412,506,75205-Oct-200904:57IA-64Not Applicable
Vsstrace.dll6.1.7600.20541123,90405-Oct-200904:57IA-64Not Applicable

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

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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

Additional file information for Windows Server 2008 R2 and for Windows 7

Additional files for all supported x86-based versions of Windows 7

File nameFile versionFile sizeDateTimePlatform
Package_for_kb975354_rtm~31bf3856ad364e35~x86~~ Applicable1,94705-Oct-200908:39Not Applicable
X86_microsoft-windows-vssapi_31bf3856ad364e35_6.1.7600.20541_none_d56e11acfc160890.manifestNot Applicable12,38905-Oct-200908:44Not Applicable

Additional files for all supported x64-based versions of Windows Server 2008 R2 and of Windows 7

File nameFile versionFile sizeDateTimePlatform
Amd64_microsoft-hyper-v-g..aller-win5x-package_31bf3856ad364e35_6.1.7600.20542_none_2ed3f910bd050e3b.manifestNot Applicable2,27306-Oct-200907:09Not Applicable
Amd64_microsoft-hyper-v-g..aller-win60-package_31bf3856ad364e35_6.1.7600.20542_none_951fd644ee15dd34.manifestNot Applicable3,36906-Oct-200907:28Not Applicable
Amd64_microsoft-hyper-v-vstack-vmms_31bf3856ad364e35_6.1.7600.20542_none_933cd6ca919d9d8b.manifestNot Applicable316,00206-Oct-200907:00Not Applicable
Amd64_microsoft-windows-vssapi_31bf3856ad364e35_6.1.7600.20542_none_318dad7ab472931d.manifestNot Applicable12,39306-Oct-200916:08Not Applicable
Package_for_kb975354_rtm~31bf3856ad364e35~amd64~~ Applicable2,94506-Oct-200916:08Not Applicable
Wow64_microsoft-windows-vssapi_31bf3856ad364e35_6.1.7600.20542_none_3be257cce8d35518.manifestNot Applicable11,45306-Oct-200916:08Not Applicable

Additional files for all supported Itanium-based versions of Windows Server 2008 R2

File nameFile versionFile sizeDateTimePlatform
Ia64_microsoft-windows-vssapi_31bf3856ad364e35_6.1.7600.20541_none_d56fb5a2fc14118c.manifestNot Applicable12,39105-Oct-200908:39Not Applicable
Package_for_kb975354_rtm~31bf3856ad364e35~ia64~~ Applicable1,95805-Oct-200908:39Not Applicable
Wow64_microsoft-windows-vssapi_31bf3856ad364e35_6.1.7600.20541_none_3be15782e8d43bc1.manifestNot Applicable11,45305-Oct-200908:39Not Applicable

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For more information about the cluster shared volumes, visit the following Microsoft website:

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Keywords: kbhyperv, kbqfe, kbhotfixserver, kbsurveynew, kbautohotfix, kbexpertiseinter, kbbug, kbfix, kb

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Article Info
Article ID : 975354
Revision : 1
Created on : 1/7/2017
Published on : 2/12/2011
Exists online : False
Views : 34