Administering Volume Snapshots

Snapshot overview and administering snapshots.

Snapshot Basics

A snapshot is a static or read-only view of a volume that represents the state of the volume at the point in time of the snapshot creation. Because a snapshot is not a replica of a volume, it does not occupy much space on the volume.

A snapshot takes no time to create, and initially uses no disk space, because it stores only the incremental changes needed to roll the volume back to the state at the time the snapshot was created. The storage used by a volume's snapshots does not count against the volume's quota.

A snapshot can be used to restore volume data to the state the volume data at the time of the snapshot creation.

You can use a snapshot for the following purposes.
  • Snapshots enable you to roll back to a known good data set and recover data in case of data corruption or accidental deletions, without the help of storage administrators. For example, before performing a risky operation on a volume, you can create a snapshot to enable rollback capability for the entire volume.
  • Create static data sets for querying and auditing.
Snapshots are stored in the .snapshot directory on the volume mount path.

You can access snapshots via NFS or the Hadoop shell.

You can create a snapshot manually, or automate the process with a schedule. If you wish to schedule the creation of snapshots, you must assign a predefined schedule.