HP P4000 9.0 HP StorageWorks P4000 SAN Solution User Guide - Page 230

Cancel the rollback operation, Deleting a snapshot, Restrictions on deleting snapshots

Page 230 highlights

1. Click Roll Back ALL Associated Volumes. Each associated volume rolls back to its corresponding snapshot. 2. Use diskpart.exe to change the resulting volume's attributes. For more information, see "Making an application-managed snapshot available" on page 218. 3. Reconnect iSCSI sessions to the volume, and restart the applications. Cancel the rollback operation If you need to log off iSCSI sessions, stop application servers, or other actions, cancel the operation, perform the necessary tasks, and then do the rollback. 1. Click Cancel. 2. Perform necessary actions. 3. Start the rollback again. Deleting a snapshot When you delete a snapshot, the data necessary to maintain volume consistency are moved up to the next snapshot or to the volume (if it is a primary volume), and the snapshot is removed from the navigation window. The temporary space associated with the snapshot is deleted. Restrictions on deleting snapshots You cannot delete a snapshot when the snapshot is: • A clone point. • In the process of being deleted or being copied to a remote management group. • The primary snapshot that is copied using Remote Copy, and you are not logged into the remote management group that it is copied to. CAUTION: Typically, you do not want to delete individual snapshots that are part of a snapshot set. To see any associated snapshots, select a snapshot, click the Details tab, and look at the Snapshot Set field. For information about snapshot sets, see "Requirements for application-managed snapshots" on page 216. Typically, you want to keep or delete all snapshots for a volume set. If you need to roll back to a snapshot, you want to roll back each volume in the volume set to its corresponding snapshot. The system gives you the option to automatically delete or roll back all associated volumes. CAUTION: Network RAID-5 and Network RAID-6 volumes require snapshots in order to achieve space utilization benefits. This means that deleting the last snapshot of a Network RAID-5 volume causes its space requirement to be the same as a Network RAID-10 (2-Way Mirror) volume. Similarly deleting the last snapshot of a Network RAID-6 volume causes its space requirement to be the same as a Network RAID-10+1 (3-Way Mirror) volume. It is possible, therefore, for the storage cluster not to have enough space to accommodate the snapshot deletion. Deleting the last snapshot of a Network RAID-5 or Network RAID-6 volume is not recommended. 230 Using snapshots

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1.
Click
Roll Back ALL Associated Volumes
.
Each associated volume rolls back to its corresponding snapshot.
2.
Use diskpart.exe to change the resulting volume's attributes.
For more information, see
Making an application-managed snapshot available
on page 218.
3.
Reconnect iSCSI sessions to the volume, and restart the applications.
Cancel the rollback operation
If you need to log off iSCSI sessions, stop application servers, or other actions, cancel the operation,
perform the necessary tasks, and then do the rollback.
1.
Click
Cancel
.
2.
Perform necessary actions.
3.
Start the rollback again.
Deleting a snapshot
When you delete a snapshot, the data necessary to maintain volume consistency are moved up to
the next snapshot or to the volume (if it is a primary volume), and the snapshot is removed from the
navigation window. The temporary space associated with the snapshot is deleted.
Restrictions on deleting snapshots
You cannot delete a snapshot when the snapshot is:
A clone point.
In the process of being deleted or being copied to a remote management group.
The primary snapshot that is copied using Remote Copy, and you are not logged into the remote
management group that it is copied to.
CAUTION:
Typically, you do not want to delete individual snapshots that are part of a snapshot set. To see any
associated snapshots, select a snapshot, click the
Details
tab, and look at the Snapshot Set field. For
information about snapshot sets, see
Requirements for application-managed snapshots
on page 216.
Typically, you want to keep or delete all snapshots for a volume set. If you need to roll back to a
snapshot, you want to roll back each volume in the volume set to its corresponding snapshot. The
system gives you the option to automatically delete or roll back all associated volumes.
CAUTION:
Network RAID
5 and Network RAID
6 volumes require snapshots in order to achieve space utilization
benefits. This means that deleting the last snapshot of a Network RAID
5 volume causes its space
requirement to be the same as a Network RAID
10 (2-Way Mirror) volume. Similarly deleting the
last snapshot of a Network RAID
6 volume causes its space requirement to be the same as a Network
RAID
10+1 (3-Way Mirror) volume. It is possible, therefore, for the storage cluster not to have enough
space to accommodate the snapshot deletion. Deleting the last snapshot of a Network RAID-5 or
Network RAID-6 volume is not recommended.
Using snapshots
230