HP Application Recovery Manager software Integration guide (March 2008)

• When Enterprise Virtual Array (EVA) VSS hardware provider is used, and the
disks array of the application system and the disk array of the backup system
are not controlled by the same Command View.
• When the Disk Array XP VSS hardware provider is used in the resync mode,
no matter if one or two disk arrays are used.
In the above situations, there is only one instant recovery scenario that is
supported. For a successful instant recovery, follow the steps:
1. Fail over Exchange Server, so that your production database resides on the
former backup system where the database copy resided before.
2. Perform instant recovery.
3. After the instant recovery session completes, fail back Exchange Server. This
action will ensure that all backup LUNs are available on the same backup
system where the database copy resides.
NOTE:
It is recommended that both production and replication server systems are using
disks of the same disk array. If this is not possible, the disks of both disk arrays
must be visible to both systems.
Enterprise Virtual Array limitations
• With the EVA provider, if there are too many source volumes selected for backup
(more than four), the creation of snapshots may take too long and VSS may fail
the snapshots creation process.
It is strongly recommended not to specify too many objects in a backup
specification, since they might reside on more than four source volumes. This
means that, for example, a Microsoft Exchange Server storage group should not
reside on more than four source volumes, and only one storage group should be
selected for backup in this case. The same limitations applies to Microsoft SQL
Server databases.
Disk Array XP limitations
• If the Disk Array XP VSS hardware provider is in the VSS compliant mode, and
there is a heavy I/O load on the disk array, the replica creation may take a long
time. Consequently, the backup session may fail.
By default, Application Recovery Manager waits for a maximum of 45 minutes
(2700 seconds) for mirrors to become synchronized. If synchronization is not
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