HP StorageWorks Storage Mirroring Recover User's Guide (T5437-96008, November 2009)

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display a prompt asking if a failover is desired. The time it takes for the Application
Manager to realize a complete source cluster failure varies greatly. At times, the prompt
can be seconds after the failure, or it might take several minutes. If you want the prompt
to appear more quickly and you know that the source cluster has failed, you can
decrease the amount of wait time by closing the Application Manager, re-opening it, and
selecting the protected pair (if it is not automatically selected).
When a failover is initiated, the following steps occur:
1. The Application Manager waits on the target replication queue to empty.
2. The exchfailover.exe utility fails over the virtual protocols of the EVS.
3. The resources are created on the target cluster.
● The resources are created in the same order as they appeared on the source
cluster.
● The resources are configured exactly as they were on the source cluster.
4. The resources are brought online.
5. The DNS failover utility is used to lock the source DNS record.
Differences in failback
The process used to failback to the source cluster is the same as any other cluster
failover method. The only difference is the EVS is now on both the source and target
clusters.
To failback to the source cluster, make sure the Physical Disk resource(s) and the IP
Address resource are online on the source cluster, then use the Storage Mirroring
Recover Application Manager to failback.
Note:
● When you bring the source cluster online, an identical network name will
still be active on the target. Because of this, when the source cluster tries
to bring up the EVS on the source, the network name resource will fail and
consequently the group will not come online on the source. You should
allow the source cluster to finish trying to bring the resources online before
using the Application Manager to failback.
● In a like-named environment with more than one DNS server, there may
be a delay contacting the source server after failback. The DNS server
used by the source cluster is updated on failback to point back to the
source server. However, if the Application Manager is running on a
machine that uses a different DNS server, it may not recognize the change
until the next DNS zone refresh.