HP StorageWorks SAN Virtualization Services Platform administrator guide (5697-0109, July 2009)

CAUTION:
• Whenever possible, use Force Resume before using Force Delete. Force Resume maintains the
synchronous mirror group structure and allows the option to resume mirroring with the failed site
after the site is recovered. A Force Delete operation deletes the synchronous mirror structure and
forces you to recreate the synchronous mirror group and the synchronous mirror group jobs.
• Single component failures can usually be recovered by using the standard management operations
of synchronous mirroring (resynchronization, resume, change operation mode, break, or delete).
Only use Force Resume and Force Delete as a last resort for multiple failures, site failures, and
extended intersite link outages.
Recovering the surviving site by using Force Resume
1. If possible, on the site that is down, turn off the power to all of the DPMs that are involved in
synchronous mirroring and the VSM server.
Turning off the power to all of the DPMs prevents the DPMs or intersite links from coming online
unexpectedly when you restore power.
NOTE:
You can also disconnect the intersite links at the end of the surviving site.
2. On the surviving site, take the necessary actions to allow the VSM to become active. If needed,
use the options in the Recovery tab on the VSM monitor.
Whenever you select an entry and click the Yes button or the OK button, make sure that the status
of the VSM is Passive. The entries from the Recovery tab are not accepted when the VSM is
stopped.
The first window on the Recovery tab asks your permission to use the surviving copy of the boot
data and to ignore the missing ones. Figure 26 shows the Recovery tab message asking if you
want the VSM to attempt to become active.
Synchronous mirroring in a single stretched domain84