HP StorageWorks SAN Virtualization Services Platform Administrator Guide (5697-0934, May 2011)

4. Assign the host permission to use the recovery virtual disks. You can do either of the following:
a. Right-click the specific DR element that you want to recover, and select Manage > Add
Host Permission to assign permission to a host to use the DR element. The host will then
use the most recent PiT available on that DR element. There is a chance, however, that
the application will not be able to use the PiT as it is. This is because mirror standard PiTs
are taken at times that are asynchronous to the application state. If this is the case and
the application cannot use the PiT, you will need to run some application-specific recovery
procedures to bring the application online. Any modifications that such utilities perform
will be written to the most recent PiT. If this procedure fails, you still have the option to
roll back to earlier PiTs or user PiTs, if available, and try once again to recover. Once
recovered, you may start deleting the older PiTs that are on that element, unless you want
to maintain them for a future merge with the main site, after recovery.
b. Test the ability to recover from every PiT before assigning presentations to production
hosts, and without modifying any PiT while testing. To test each PiT for this purpose, create
a snapshot on the PiT, and present it to the host running the application. If the application
works with the snapshot, you know that the host can also work directly with the PiT from
which the snapshot was created. Any modification that the application writes to the
snapshot during the validation process does not modify the PiT. If your recovery attempt
fails, you can delete the snapshot, create a new one, and start again. After you have
found the best PiT for recovery and verified the steps that you need to perform on the
application, you can delete the snapshot. You should then roll back to the PiT you want
to use, and then expose the DR element with all its remaining PiTs to a host. To expose
the DR element to a host, right click the DR element and select Manage > Add Host
Permission. Once recovered, you may start deleting the older PiTs that are on the DR
element, unless you want to maintain them for a future merge with the main site, once
recovered.
When you have rebuilt the main site, you can run the following procedure to fail back to the new
main site without losing production data.
To restore production to a rebuilt main site:
1. Reconnect the SVSP domains.
2. Connect to the DR site's SVSP domain and create new async mirror groups and tasks to mirror
the production virtual disks on the DR site to new destination virtual disks on the new main
site.
84 Site failover recovery with asynchronous mirrors