Guidelines for Protecting Data using HP StorageWorks Storage Mirroring with Volume Shadow Copy Service (VSS) (T2558-96332, March 2009)

1 Solution Overview
Volume Shadow Copy Service (VSS) on Microsoft® Windows® Server 2003 allows a snapshot (or
shadow copy) of all files on a volume to be made at regular, scheduled intervals. Shadow copies are
useful for recovery of lost or corrupted files on a shared resource without the need for administrative
intervention. However, shadow copies do not replace backups. If the drive that holds the shadow
copies fails, the shadow copies are lost.
Storage Mirroring provides real-time enterprise data protection and replication. It provides disaster
recovery and high availability for the data, thus enhancing the functionality of VSS.
This document describes how Storage Mirroring can be used with VSS on Microsoft Windows Server®
2003 to offer user-initiated file restoration, in addition to the standard protection that Storage Mirroring
offers for production data and applications. When VSS is enabled on both the source and target,
VSS takes snapshots of the same data on both the source and target. In the event of failover, previous
versions of the same data are still available on the target.
For more information about data protection using Storage Mirroring, see the NSI Solutions with
Microsoft Volume Shadow Copy Service white paper, available from www.microsoft.com
Configurations
The following configurations provide options for ways to enhance VSS using Storage Mirroring.
• VSS on Source Server: Storage Mirroring provides real-time protection of production data and
provides high availability for production applications. VSS is enabled on the source machine to
provide user-initiated file recovery on the source server. However, Storage Mirroring does not
provide protection for VSS snapshots
• VSS on Target Server: Storage Mirroring provides real-time protection of production data and
provides high availability for production applications. VSS creates shadow copies of the replicated
data on the target server. Creating shadow copies only on the target relieves the production
server of the overhead associated with VSS.
In this configuration, the users would not have access to restoring files; however, at a user’s request,
the administrator can use the snapshots on the target to restore a user’s file(s).
Guidelines for Protecting Data using HP StorageWorks Storage Mirroring with Volume Shadow Copy
Service (VSS) 11