After you restart the Windows Server 2003-based node that hosts a shadow copy disk, the signature on the shadow copy disk unexpectedly changes

Consider the following scenario. In a cluster environment, you create a shadow copy snapshot for a disk on a node that is running Microsoft Windows Server 2003. You use a hardware-assisted Volume Shadow Copy Service (VSS) to create the shadow copy snapshot. However, after you restart the node that hosts the shadow copy disk, the signature on the shadow copy disk unexpectedly changes.

When this problem occurs, the shadow copy disk cannot come online. Therefore, the other resources that depend on the resources that are on the shadow copy disk do not work.

This problem occurs if one of the following is installed:

• A VSS-specific update that has a file version that is either later than or equal to the file version that is described in the following Microsoft Knowledge Base article:
  891957� Update is available that fixes various Volume Shadow Copy Service issues in Windows Server 2003
• Windows Server 2003 Service Pack 2

This problem occurs because the volume management module does not remove certain temporary data from the snapshot as expected. The temporary data causes the signature to be changed when the node that hosts the shadow copy disk is restarted.

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 this specific problem. 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.

Prerequisites

To apply this hotfix, you must have Windows Server 2003 Service Pack 1 or Windows Server 2003 Service Pack 2 installed on the computer. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

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 2003 with Service Pack 1, x86-based versions

Windows Server 2003 with Service Pack 2, x86-based versions

Windows Server 2003 with Service Pack 1, Itanium-based versions

Windows Server 2003 with Service Pack 2, Itanium-based versions

Windows Server 2003, x64-based versions

Windows Server 2003 with Service Pack 2, x64-based versions

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

Windows Server 2003 Service Pack 1 introduced a preventive measure to avoid the disk signature collision that the VSS snapshot causes. The system tries to proactively change the signature on the shadow copy disk during the VSS snapshot creation. To do this, the system puts temporary data in the snapshot. The temporary data is removed after the snapshot is created successfully.

However, after the update that is described in KB891957 or a later version is applied, the temporary data is not removed as expected after the snapshot is created. This behavior causes the disk signature to unexpectedly change.

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