HP XP Cluster Extension Software Administrator Guide

disk pairs have been paired. This feature supports automatic resynchronization of locally split
Business Copy disk pairs only. You must specify MU numbers for resynchronization by using
the BCResyncMuListA and BCResyncMuListB objects for data centers A and B.
Setting automatic recovery for rolling disaster protection
If the AutoRecover object is set to YES, XP Cluster Extension automatically resynchronizes the
Continuous Access disk pairs to update the remote disks. If rolling disaster protection is also enabled,
it suspends the Business Copy disk pair that is attached to the remote Continuous Access disk.
If the remote RAID Manager instance is not running or cannot be reached, the remote Business
Copy disk pair cannot be suspended. If this occurs, XP Cluster Extension continues the application
service activation without automatic resynchronization of the Continuous Access disk pair and
without the suspending of the Business Copy disk pair. In this case, the Continuous Access disk
pair must be recovered manually.
Using the pair/resync monitor with rolling disaster protection
If the ResyncMonitor object is set to YES, the pair/resync monitor does not use Business Copy pairs
to recover suspended or failed Continuous Access disk pairs.
To protect the remote volume of an out-of-sync Continuous Access disk pair against rolling disasters,
use the pair/resync monitor's default settings. Resynchronize the Continuous Access disk pair
manually after splitting off the Business Copy disk pair.
Restoring server operation for rolling disaster protection
Rolling disaster protection automatically recovers the PAIR state of the Continuous Access disk pair
of an application service. Before you fail over (or fail back) an application service from one data
center to the other, you must restore the server operation. After you restart the server, also start the
RAID Manager instance used to manage the Continuous Access disk pairs on those servers. This
enables rolling disaster protection to work correctly during a recovery failover/failback operation.
“Disaster-tolerant configuration with rolling disaster protection” (page 61) depicts a fully configured
XP Cluster Extension environment that uses rolling disaster protection. The Business Copy disk pairs
are specified as 0 in the XP Cluster Extension BCMuListA and BCMuListB objects. See “APPLICATION
objects ” (page 50) for more information about these objects.
60 Advanced XP Cluster Extension configuration