HP StorageWorks 2300 Modular Smart Array reference guide (500911-001, January 2009)

64 Provisioning the system
Rolling back a volume
You can roll back (revert) the data in a volume to the data that existed when a specified snapshot was
created. You also have the option of including its modified data (data written to the snapshot since it was
created). For example, you might want to take a snapshot, mount it for read/write, and then install new
software on the snapshot for testing. If the software installation is successful, you can roll back the volume
to the contents of the modified snapshot.
CAUTION:
• Before rolling back a volume you must unmount it from data hosts to avoid data corruption. If you want
to include snapshot modified data in the roll back, you must also unmount the snapshot.
• Whenever you perform a roll back, the data that existed on the volume is replaced by the data on the
snapshot; that is, all data on the volume written since the snapshot was taken is lost. As a precaution,
take a snapshot of the volume before starting a roll back.
Only one roll back is allowed on the same volume at one time. Additional roll backs are queued until the
current roll back is complete. However, after the roll back is requested, the volume is available for use as if
the roll back has already completed.
Figure 5 Rolling back a master volume
To roll back a volume
1. Unmount the volume from hosts.
2. If the roll back will include snapshot modified data, unmount the snapshot from hosts.
3. In the Configuration View panel, right-click a volume and select Provisioning > Roll Back Volume.
MasterVolume-1
Snap Pool-1
Snapshot-1
(Wed Jan 18 22:37:17 2008)
Preserved Data
Modified Data
(Thur Jan 22 21:20:30 2008)
MasterVolume-1
Snap Pool-1
Snapshot-1
Modified Data
(Thur Jan 22 21:20:30 2008)
When you use the rollback feature, you
can choose to exclude the modified data,
which will revert the data on the master
volume to the preserved data when
the snapshot was taken.
(Wed Jan 18 22:37:17 2008)
Preserved Data
Or you can choose to include the modified
(write) data since the snapshot was taken,
which will revert the data on the master volume
to the current snapshot.