HP StorageWorks SAN Virtualization Services Platform administrator guide (5697-0204, January 2010)

3. On the surviving site, for every failed synchronous mirror group, right-click the mirror group, and
select Manage > Recovery > Force Resume.
4. To run Force Resume on all of the failed synchronous mirror groups, right-click the synchronous
mirror entity in the left pane, and select Recovery > Force Resume All.
Force Resume assigns the local synchronous mirror task to be the new primary task for the group,
marks the other tasks as secondary, and brings the synchronous mirror virtual disk to a state of
Normal.
If the mirror mode of the synchronous mirror group is Automatic Failover, the host is able to access
the virtual disk.
If the mirror mode is Synchronous Always, the host cannot use the virtual disk because one task
has failed. In this case, you can either change the mirror mode of the synchronous mirror group
to Automatic Failover (the preferred action) or break all of the failed tasks.
Re-establishing the connection with the recovered site after Force Resume
1. Make sure that all of the components at the recovered site are online except for the DPM that
you deliberately powered off.
2. Make sure that the VSM servers at both sites are online and see each other.
3. Turn on the power to the DPM at the recovered site. The DPM at the recovered site will join the
system as a passive DPM for all virtual disks assigned to that DPM group.
4. Initiate resynchronization or resume for all failed synchronous mirror tasks. The DPMs use the
currently active task as the source for synchronizing the task at the recovered site. The DPM might
decide to fail this resynchronization request in case the failed task is a more recent update than
the surviving task that was recovered by Force Resume. In this case, you must break this failed
task and use it as a standalone virtual disk.
Recovering the surviving site by using Force Delete
CAUTION:
Using Force Delete on a synchronous mirror deletes the synchronous mirror structure.
1. If possible, at 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 the DPMs prevents the DPMs from coming online unexpectedly when
the power is restored.
NOTE:
You can also disconnect the intersite links at the end of the surviving site.
2. At 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 VSM has a status of 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 ignore the missing ones.Figure 38 shows the Recovery tab message asking if you want
the VSM to attempt to become active.
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