Storix Software SBAdmin TSM Edition Users Guide - Manual (Page 50)

13. Snapshot Backups
Snapshot feature is available only for AIX systems running AIX 6.1 and later, for
Linux data contained in LVM logical volumes, and Solaris data contained in ZFS
datasets.
SBAdmin provides an option of creating a “point-in-time” backup of data contained in logical volumes and
filesytems. This is typically referred to as a
snapshot backup. Although the feature is available for AIX, Solaris
and Linux systems, the internal process differs to some extent:
• For
Linux, a LVM snapshot logical volume is created for each logical volume to be backed up. Snapshots
may be created for any logical volume, whether or not it contains a filesystem. This snapshot LV is
generally smaller than the original LV, but large enough to contain any changes which occur to the original
logical volume for the duration of the backup.
• For
AIX, snapshots are available only for logical volumes containing JFS2 (Extended JFS) filesystems. For
AIX 6.1, only internal snapshots are supported (i.e. snapshots are recorded within the logical volume itself),
and at AIX 6.2 and later, either internal or external snapshots may be used (external snapshots created a
temporary snapshot logical volume similar to Linux snapshots described above).
• For
Solaris, snapshots are available on ZFS filesystems and ZFS volumes. Snapshots may be created for
any dataset, whether or not it contains a filesystem.
As the backup is performed, original data to be changed by another process is first copied to the snapshot
device (or internal snapshot area for AIX 6.1), and the data from the snapshot device is backed up in place of
the changed data. When the backup is complete, the snapshot is simply removed. Any process which reads or
writes data to the original device (or filesystem within) during the backup will use the most up-to-date data,
while the backup contains only the original data as it was when the backup began.
Enabling Snapshot Backups
Snapshot backups are configured on each client a backup will be performed. On each client, you may specify
each logical volume/ZFS dataset for which a snapshot is created, or you may indicate that all logical
volumes/ZFS datasets will use snapshot backups, when possible.
Although logical volumes and filesystems may be configured to allow snapshot
backups, a snapshot will not be created by default when a backup job is run. You
must also select to Perform Snapshot Backup? from the
job configuration screen
before a snapshot backup will be performed.
To enable snapshot backups, select the following from the menu bar:
Configure !Snapshot Backups
The configuration screen will appear as in the following sample:
Storix System Backup Administrator 50 Version 8.2 TSM Edition User Guide