How VSS Works with Tivoli Storage Manager for Copy Server and IBM System Storage Hardware

Published 28 August 2006

Authors: Charlotte Brooks


This technote summarizes the steps that occur when a VSS Exchange backup is made by an off-loaded server to Tivoli Storage Manager, using Tivoli Storage Manager for Copy services and Tivoli Storage Manager for Mail Data Protection for Exchange, along with the IBM System Storage VSS hardware provider for SAN Volume Controller, DS6000, and DS8000. In this configuration, the Exchange server initiates the backup and creates the snapshot onto IBM disk. Then the off-loaded server (a separate Microsoft Windows 2003 system) backs up the data to Tivoli Storage Manager storage.


The following steps are performed by the Microsoft VSS in conjunction with FlashCopy when a backup application initiates a request for backup on an IBM disk system (specifically the SAN Volume Controller, DS6000, or DS8000).

  • VSS retrieves a list of volumes from the storage system and selects appropriate target volumes from the free pool (VSS_FREE).
  • VSS moves the target volumes to the reserved pool (VSS_RESERVED) and the Exchange database suspends writes.
  • VSS issues a FlashCopy from the source volumes to the target volumes. The FlashCopy is performed on the hardware under the direction of the VSS hardware provider.The FlashCopy is made as a transportable nonpersistent snapshot.
  • The database resumes writes after the FlashCopy is complete. The Exchange server now has no further involvement in the operation.
  • VSS assigns the target volumes to the off-loaded server’s HBAs. Microsoft Windows mounts the volumes on the off-loaded server.
  • The VSS requestor reads the data from the target volumes and copies it to Tivoli Storage Manager server storage.
  • Once the backup to Tivoli Storage Manager is complete, Microsoft Windows un-mounts the volumes and VSS unassigns the target volumes from the backup server’s HBAs.
  • VSS assigns the target volumes back to the free pool (VSS_FREE). They are available for use in other VSS operations.

Special Notices

This material has not been submitted to any formal IBM test and is published AS IS. It has not been the subject of rigorous review. IBM assumes no responsibility for its accuracy or completeness. The use of this information or the implementation of any of these techniques is a client responsibility and depends upon the client's ability to evaluate and integrate them into the client's operational environment.

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