Windows Server 2008 Hyper-V VSS writer is not used during a backup job because of corrupted or invalid virtual machine configuration files

Consider the following scenario:

• In Windows Server 2008, "Microsoft Hyper-V VSS Writer" is not listed when you run the vssadmin list writers command.
• When you perform a backup of the Hyper-V virtual machines, the following event is logged to the Hyper-V-VMMS event log:

  Log Name: Microsoft-Windows-Hyper-V-VMMS-Admin
  Source: Microsoft-Windows-Hyper-V-VMMS
  Event ID: 10107
  Description:
  An error occurred while identifying the Hyper-V VSS writer. Check for any corrupt or invalid configuration files and try again.

In this scenario, the backups of the virtual machines may be inconsistent because the Hyper-V VSS writer is not used during the backup job.

This problem occurs because of corrupted or invalid virtual machine configuration files.

Service Pack Information

To resolve this problem, obtain the latest service pack for Windows Server 2008. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Update information

The following file is available for download from the Microsoft Download Center:

Download the Update for Windows Server 2008 x64 Edition (KB956697) package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=5EB76BDA-8794-412A-9FD4-1BCCBBC34C82)

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

Release Date: September 9, 2008

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

Prerequisites

You must have Windows Server 2008 installed to apply this update.

Restart requirement

You do not have to restart the computer after you apply this update.

Update replacement information

This update does not replace any other updates.

File information

The English version of this update 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 Vista and Windows Server 2008 file information notes

• The .manifest files and the .mum files that are installed in each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. These files and their associated .cat (security catalog) files are critical to maintaining the state of the updated component. The .cat files are signed with a Microsoft digital signature. The attributes of these security files are not listed.
• The binary files that apply to a specific product, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
  
  Collapse this tableExpand this table

  Version	Product	Milestone	Service branch
  6.0.6000.16xxx	Windows Server 2008 SP1	SP1	GDR
  6.0.6001.22xxx	Windows Server 2008 SP1	SP1	LDR

For all supported 64-bit versions of Windows Server 2008

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

After you apply this update, the following event will continue to be logged. However, you can safely ignore the event.

Log Name: Microsoft-Windows-Hyper-V-VMMS-Admin
Source: Microsoft-Windows-Hyper-V-VMMS
Event ID: 10107
Description:
An error occurred while identifying the Hyper-V VSS writer. Check for any corrupt or invalid configuration files and try again.

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

Additional file information for Windows Server 2008

Additional files for all supported 64-bit versions of Windows Server 2008