In Windows Server 2008, you receive the following error:
In Windows Server 2008 R2, you receive the following error:
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.
- The volume used to store the system state backup needs twice the amount of free space as the size of the system state backup until the backup completes.
- Any writes on target volume with shadow copies will increase the diff area size. If the diff area is bounded, it may cause deletion of shadow copies.
- Incremental backups leaves shadow copies behind, it will cause side effect as point 1.
- Backup stores different versions as shadow copies, it will cause side effect as point 1.
Registry entry to enable system state backups to critical volumesWarning 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:
If all the previous prerequisites are not met, you may see shadow-copy loss when you perform a backup. In worst condition backup itself may fail because of the snapshot from which backup was taken is becoming lost while writing the backup.
Steps to reproduce the behavior
- Install Windows Server 2008 or Windows Server 2008 R2.
- 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:Drive_Letter:Note In this command, Drive_Letter represents a critical volume. Examples of a critical volume include the boot volume and the system volume. Typically, this critical volume is drive C.
Backup and Recovery Overview for Windows Server 2008 R2