HP Storageworks Storage Mirroring Console user's guide (T2558-96330, April 2009)

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Virtual hard disks
Storage Mirroring for Hyper-V monitors the virtual disks of a protected virtual machine for changes
to the disk layout. If a virtual hard disk (VHD) is added to the virtual machine, Storage Mirroring for
Hyper-V will update the protection job to include the new VHD. This will start a file difference mirror.
If a VHD is removed from a protected VM, Storage Mirroring for Hyper-V will correctly update the
configuration of the replica VM to include the new disk layout. However, the VHD will not be removed
from the protection job until it is deleted from the source machine, or the job is removed and
re-created.
Performing failover
After the protection job completes the initial synchronization, failover will be enabled. To initiate
failover, select the connection and click the Failover button on the Monitor Connections page.
When you select the Failover button, the following dialog box appears.
From here, you can select the type of failover to perform.
 Live failover—Select this option to perform a live failover with network connectivity to the target
replica virtual machine. Live failover will shut down the source virtual machine (if available), stop
the protection job, and start the replica virtual machine with full network connectivity.
 Test failover—Select this option to perform a test failover without network connectivity to the
target replica virtual machine. Test failover will leave the source virtual machine online, suspend
the protection job, and start the replica virtual machine on the target with no network
connectivity. This feature allows you to periodically test the replica virtual machine to verify that
it is working correctly.
After you select the type of failover to perform, click Failover.
Undoing failover
Once a live or test failover has been performed, it is possible to undo the failover by clicking on the
Undo Failover button. Undoing failover will do the following:
1. The replica virtual machine will be shut down
2. The source virtual machine will be restarted (if it was shutdown with a live failover)
3. The protection will be restarted (a file difference mirror will be performed)
NOTE: All changes made to the replica virtual machine while the job is in a failed over state will
be lost when an Undo is performed.