Microsoft does not support the use of Volume Shadow Copy Service to backup guest machines by way of a Virtual Server 2005 host computer (867592)

INTRODUCTION

Microsoft does not support using Volume Shadow Copy Service (VSS) on a computer that is running Microsoft Virtual Server 2005 to back up a running guest virtual machine. If you try to use VSS on a Virtual Server 2005 host computer, your guest backups may be unreliable or corrupted.

Note VSS is supported on Virtual Server 2005 guest virtual machines. Additionally, you can use VSS to back up all other applications on the host computer that support the VSS infrastructure.

MORE INFORMATION

VSS requires a snapshot of the program state. To create this snapshot, the program must typically reach a consistent state and then become inactive to enable VSS to create the snapshot.

Virtual Server programs run in a volatile state because their extensive optimizations deal with large flows of transactions and of messages. Because Virtual Server programs keep their data in a constant state of flux between memory and disk, it may be difficult to locate data that must be archived.

Without the support for the interfaces that VSS provides to take a snapshot of the program state, VSS cannot perform the shadow copy of the host computer and guarantee that a consistent state of the guest virtual machine will be obtained. If you use VSS without the support for the interfaces, you may cause data corruption.