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About administration of instant snapshots

Veritas Volume Manager (VxVM) provides the capability for taking an image of a volume at a given point in time. Such an image is referred to as a volume snapshot.

Instant volume snapshots allow you to make backup copies of your volumes online with minimal interruption to users. You can then use the backup copies to restore data that has been lost due to disk failure, software errors or human mistakes, or to create replica volumes for the purposes of report generation, application development, or testing.

The following types of instant volume snapshots are supported for use with application volumes created by Veritas Intelligent Storage Provisioning (ISP):

• Full-sized instant snapshots require an empty volume to be prepared for use as the snapshot volume. The length of this volume must be the same as that of the volume whose snapshot is being taken. A snapshot volume can be created in either a data pool or in a clone pool.
• Linked break-off snapshot volumes differ from full-sized instant snapshots in that they can be set up in a different disk group from the data volume. This makes them especially suitable for off-host processing applications where you may want to create the snapshot on storage with different characteristics from that used for the data volumes.
• Space-optimized instant snapshots require less space than a full-sized instant snapshot but they cannot be dissociated from their original volume nor can they be moved into a different disk group. A space-optimized snapshot uses a storage pool or cache, which can be shared by one or more other space-optimized snapshots. You must set up the cache and the space-optimized snapshot volume in advance of creating any space-optimized snapshots.

See Creating instant snapshots.

For details of how to use volume snapshots to implement off-host online backup, see the Veritas Storage Foundation Intelligent Storage Provisioning Solutions Guide.

For more information about instant volume snapshot features, see the section "Understanding Veritas Volume Manager" in the Veritas Volume Manager Administrator's Guide.

Full details of how to recover from failures of instant snapshot commands may be found in the "Recovery from failure of instant snapshot operations'' section of the Veritas Volume Manager Troubleshooting Guide.

Most VxVM commands require superuser or equivalent privileges.