HP StorageWorks P9000 Cluster Extension Software Administrator Guide (TB534-96009, February 2011)

7 Advanced P9000 Cluster Extension configuration
This chapter describes advanced P9000 Cluster Extension configuration procedures.
Implementing rolling disaster protection
To implement rolling disaster protection, create Business Copy disk pairs for the local Continuous
Access disks.
• Create the Business Copy disk pairs using the paircreate command with the –m noread
option. This option ensures that Business Copy disks are unavailable to other services and
reserved for rolling disaster protection only.
• Map the Business Copy S-VOLs to a backup server, not to the local cluster node. When P9000
Cluster Extension suspends the Business Copy pairs, they become available to the local server,
which could result in duplicated volumes, disk group IDs, or signatures.
CAUTION: You must ensure that at least one Business Copy disk pair is in PAIR state. If rolling
disaster protection is enabled and none of the Continuous Access mirrored disk pairs have a
Business Copy disk pair that is in PAIR state, P9000 Cluster Extension returns a global error, and
you will not be able to activate the application service.
You can use forceflag to start the application service. See “Enabling write access regardless
of disk pair state” (page 96). In this case, P9000 Cluster Extension disables rolling disaster
protection.
Using RAID Manager with rolling disaster protection
Rolling disaster protection does not require that you define Business Copy disk pairs in the RAID
Manager horcmX.conf files. P9000 Cluster Extension uses the MU number to monitor and control
associated Business Copy pairs. You must create a RAID Manager configuration file to control the
Business Copy disk pairs that are outside P9000 Cluster Extension control.
P9000 Cluster Extension Software cannot suspend Business Copy disk pairs on the remote disk
array in the remote data center if the RAID Manager instance in the remote data center is not
running or not reachable.
Setting P9000 Cluster Extension objects to enable rolling disaster protection
To enable rolling disaster protection with Business Copy, set the BCEnabledA and BCEnabledB
objects for data centers A and B. When these objects are set to YES, rolling disaster protection is
enabled and P9000 Cluster Extension checks whether the configured Business Copy disk pairs
are in PAIR state. Before initiating the resynchronization operation, P9000 Cluster Extension
suspends specified Business Copy disk pairs that are in PAIR state. For information on setting P9000
Cluster Extension objects, see “User configuration file and P9000 Cluster Extension objects”
(page 79).
When using rolling disaster protection, note the following:
• If the BCEnabledA and BCEnabledB objects are set to YES, you must configure specific Business
Copy disk pairs using MU numbers. The MU number defines one of the many disk pair
relationships you can create with Business Copy disk pairs. You can specify as many MU
Implementing rolling disaster protection 93