Microsoft KB Archive/944530

= Error message when you try to perform a system state backup in Windows Server 2008: &quot;ERROR - The location for backup is a critical volume&quot; =

Article ID: 944530

Article Last Modified on 12/10/2007

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APPLIES TO


 * Windows Server 2008 Datacenter
 * Windows Server 2008 Enterprise
 * Windows Server 2008 for Itanium-Based Systems
 * Windows Server 2008 Standard

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Beta Information
This article discusses a beta release of a Microsoft product. The information in this article is provided as-is and is subject to change without notice.

No formal product support is available from Microsoft for this beta product. For information about how to obtain support for a beta release, see the documentation that is included with the beta product files, or check the Web location where you downloaded the release.

Important This article contains information about how to modify the registry. Make sure that you back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify 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 XP and Windows Vista



SYMPTOMS
When you try to perform a system state backup to a volume on which the system state file resides, you receive the following error in Windows Server 2008:

ERROR - The location for backup is a critical volume.



CAUSE
This behavior occurs because system state backups to critical volumes are blocked in Windows Server 2008.



RESOLUTION
You can change the default behavior of Windows Server 2008 by adding a registry entry. You must also verify that the following prerequisites are met before you perform a system state backup to a critical volume.

Prerequisites to perform system state backups to critical volumes

 * Make sure that the target volume has no shadow copy before the backup starts.
 * If a system state backup is stored on a source volume, backup settings should be configured for full backups. By default, settings are configured for full backups.
 * Periodically check that no other user or program maintains a shadow copy on the target volume.
 * Do not keep volume level backups and system state backups in the same location.

Registry entry to enable system state backups to critical volumes
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To enable the system state backup files to be targeted to critical volumes, you must set the value of the AllowSSBToAnyVolume registry entry under the following registry subkey:

Set the value of this entry as follows:

Name: AllowSSBToAnyVolume

Data type: DWORD

Value data: 1

Note When this value is set to 1, system state backups to any volume are enabled. To revert to the default behavior, set the value to 0.



MORE INFORMATION
The restriction to target the system state backup to any volume is a new feature in Windows Server 2008.

Steps to reproduce the behavior
 Install Windows Server 2008. Install the Windows Server Backup feature from the Server Manager snap-in. Perform a system state backup by typing the following command at a command prompt:

wbadmin start systemstatebackup -backuptarget: :

Note In this command,  represents a critical volume. Examples of a critical volume include the boot volume and the system volume. Typically, this critical volume is drive C.

