HP StorageWorks SAN Virtualization Services Platform Manager user guide (AG781-96017, March 2009)

4. Select the Source Virtual Disk/Snapshot/VDG tab. The Source Virtual Disk/Snapshot/VDG tab
displays the virtual disk, snapshot, or VDG on which the PiT was created.
5. Double-click the source virtual disk, snapshot, or VDG. The tabs area now displays tabs relating
to the source virtual disk, snapshot, or VDG. You have reached the root of the hierarchy.
6. Select the Hierarchy tab. The Hierarchy tab displays the original source virtual disk or VDG and
the entire snapshot hierarchy dependent on that source element, including the snapshot you
started with, which you can identify by name in the hierarchy.
To trace a PiT to the root of its hierarchy:
1. If you are viewing the PiT in the PiT tab of a virtual disk or VDG, the selected virtual disk or VDG
is both the source of the PiT and the root of the hierarchy. Select the Hierarchy tab for the virtual
disk or VDG. The Hierarchy tab displays the original source virtual disk or VDG and the entire
snapshot hierarchy, dependent on that source element, including the PiT you started with, which
you can identify by name in the hierarchy.
2. If you are viewing the PiT in the PiT tab of a snapshot, select the Source PiT tab for the snapshot.
The Source PiT tab displays the PiT from which the snapshot was created.
3. Double-click the PiT in the Source PiT tab. The tabs area now displays tabs relating to that PiT.
4. Select the Source Virtual Disk/Snapshot/VDG tab. The Source Virtual Disk/Snapshot/VDG tab
displays the virtual disk, snapshot, or VDG on which the PiT was created.
5. Double-click the source virtual disk, snapshot, or VDG. The tabs area now displays tabs relating
to the source virtual disk, snapshot, or VDG. You have reached the root of the hierarchy.
6. Select the Hierarchy tab. The Hierarchy tab displays the original source virtual disk or VDG and
the entire snapshot hierarchy dependent on that source element, including the PiT you started
with, which you can identify by name in the hierarchy.
Rolling back virtual disks and VDGs
Rollback is a recovery operation that removes all data modifications that were made to a virtual disk,
VDG, or VDG snapshot since the creation of a specified PiT. The snapshot structure preceding the
creation of the selected PiT is maintained. Rollback is enabled only when the virtual disk, VDG, or
VDG snapshot has a snapshot structure that includes only PiTs and no snapshots. Rollback can be
activated using any PiT from a virtual disk, VDG, or VDG snapshot. All data and PiTs with timestamps
later than the specified PiT are destroyed.
To roll back a virtual disk, VDG, or VDG snapshot:
1. Remove all snapshots from all PiTs on the virtual disk, VDG, or VDG snapshot.
2. Unmount the virtual disk, VDG, or VDG snapshot on all hosts that are using it. Perform any other
steps for rollback described in the user manual for using the specific operating system with VSM.
CAUTION:
Do not perform a rollback while the application using the virtual disk or VDG is online,
because data integrity will not be maintained, since rollback makes the server cache obsolete
because the content of the device is changing. Just before the rollback, the application is
presented with the current data. Immediately after the rollback, the application is presented
with the data of a PiT that may be a day or two old. Therefore, unmount the virtual disk or
VDG on all hosts that use it prior to performing rollback.
Using snapshots228