HP Data Protector A.06.00 additional writers and HP StorageWorks Disk Array XP support for Microsoft Volume Shadow Copy Service integration

If backup sessions are lengthy and there is a possibility that the VSS backup
window will not be met, it is highly recommended that you first switch the Disk
Array XP VSS hardware provider to resync mode. Afterwards, consecutively run
backup sessions until the backup session count reaches the current value of the
Number of replicas rotated option. This will start creating disk mirrors on Disk
Array XP that will be used in scheduled backups. Shadow copy creation failures
or timeouts in these backup sessions can be ignored.
• There is a problem with Microsoft Exchange Server 2007 when running in a CCR
environment with Disk Array XP as the VSS hardware provider, and where the
backup system is the virtual server. In such a set-up, if there is a failover, the
backup system may change the physical node on which the virtual server runs.
Such a physical node change may occur in two cases:
• When backup sessions are configured to always use the system where the
database copy resides (in the GUI, the Exchange Replication Service instance
is selected as the backup object, and the additional Exchange option Revert
to active node on failure is selected).
• When the system where the production database resides is used as the backup
system.
The problem does not occur in a set-up where the backup system is a physical
node. In such a set-up, if there is a failover, the next backup session will fail to
rotate replicas that were used in the oldest session. Such replica rotation failure
should not prevent the current session from succeeding. Consider the following:
• If only one disk array is used, ensure that the VSS hardware provider does
not run out of disk space (LUNs that belong to secondary volumes (S-VOLs))
due to replica rotation failure.
• If two disk arrays are used, ensure that the second array is configured in the
same way as the first one.
As soon as the old backup system is up and running, use the omnidbvss
command to manually delete all the sessions that should have been deleted in
the replica rotation process. Do not use tools like Command View XP or RAID
Manager XP for this purpose. Do not delete references from the ZDB database
before you make sure that all LUNs that had been created in that backup session
have been deleted from the array.
• If the Disk Array XP VSS hardware provider is in resync mode, and the backup
system is configured as the virtual server in a quorum cluster, create a host group
on the disk array that contains host bus adapter (HBA) World Wide Names
(WWNs) from all physical systems in your cluster.
If such a host group is not created, your backups may fail after the cluster fails
over from one physical node to the other. If a failover occurs, the backup session
will fail to rotate the oldest replica and will not free the MU number that has been
HP Data Protector A.06.00 additional writers and HP StorageWorks Disk Array XP
support for Microsoft Volume Shadow Copy Service integration 75