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

Testing a DR site or switching between sites
In an actual disaster event, you must use the detach feature rather than the split feature to stop
tasks so that you can resume production from destination virtual disks. However, when you want
to test failover and failback to and from your DR site, you can take steps to ensure that no data is
lost. These are the same steps that you would use if you need to perform a planned switchover
from one site to another.
To fail over from the main site to the DR site:
1. Plan a downtime window, based on the organization’s schedule and the amount of source
data waiting to be replicated.
2. Shut down the application at the scheduled time.
3. Unmount the virtual disk on the host.
4. Log in to the main site's SVSP domain.
5. Remove the host’s permission to access the source virtual disk of an async mirror group.
6. Create a user PiT on the group.
7. Wait until the PiT you created is copied to the destination.
8. Suspend the group.
9. Split the group.
10. Log in to the DR site's SVSP domain.
11. Assign the host permission to use the mirrored virtual disk.
12. Merge the mirrored virtual disk without enabling rollback. Specify the name of the original
virtual disk on the main site as the destination. VSM creates an async mirror group, mirroring
from the DR site to the main site.
To fail back from the disaster recovery site to the main site:
1. Plan a downtime window, based on the organization’s schedule and the amount of data
waiting to be replicated.
2. Shut down the application at the scheduled time.
3. Unmount the virtual disk on the host.
4. Log in to the DR site's SVSP domain.
5. Remove the host’s permission to access the virtual disk. Since the virtual disk has PiTs, this
involves either disconnecting the host or powering the host down, and deleting the host from
the host list once its status changes to Absent.
6. Create a user PiT.
7. Wait until the PiT you created is copied to the destination, which is the main site.
8. Suspend the group.
9. Split the group.
10. Log in to the main site's SVSP domain.
11. Assign the host permission to use the original virtual disk.
12. Merge the original virtual disk without enabling rollback. Specify the name of the virtual disk
on the DR site as the destination. VSM creates an async mirror group, mirroring from the main
site to the disaster recovery site.
Failing over to the DR site and back to the main site after a problem
If you have established a DR site and you experienced a problem on your main site, but your main
site is not destroyed, these procedures switch production to your DR site and then restore production
to your main site after you fix the problem.
To recover an application using the DR site:
1. Log in to the DR site's SVSP domain.
2. Detach the tasks coming into the SVSP domain.
82 Site failover recovery with asynchronous mirrors