6 Snapshots and Clones

Note:

Cloning is a licensed feature for certain models. For details, refer to the "Oracle Software License Agreement ("SLA") and Entitlement for Hardware Systems with Integrated Software Options" and the Licensing Information User Manual for the software release.

Using snapshots and clones, you can make point-in-time copies of a share or project. These copies can be useful as backups or as different working versions.

A snapshot is a read-only copy of a filesystem, LUN, or project. Taking a project snapshot is equivalent to snapshotting all of the shares in the project. A snapshot takes up no additional space when it is first created, but as the active share changes, the snapshot takes up additional space, with a maximum equivalent to the size of the share at the time the snapshot was taken.

A clone is a writable copy of a filesystem or LUN snapshot and can be treated as an independent share. Clones of projects are not supported. Like a snapshot, a clone consumes no additional space when it is first created, but as new data is written to the clone, the space required for the changes are associated with the clone.

You can take snapshots manually, or you can set a schedule so that snapshots are taken automatically every half-hour, hour, day, week, or month. Some snapshots are taken by the appliance automatically during replication updates; these will appear on the snapshot page with .ndmp and .rr in their names.

Note:

When the file retention feature, which is different from the snapshot retention feature, is used with snapshot rollback, certain restrictions can apply. Rollback can be performed on a filesystem with the privileged file retention policy, even when unexpired retained files exist. Filesystems with the mandatory file retention policy can never be rolled back, even when all retained files have expired. For more information, see File Retention Management.

For information about snapshot space management, see:Snapshot Space Management.

To take manual snapshots or schedule automatic snapshots of projects or shares, use the following tasks:

• Taking a Snapshot - BUI, CLI

• Scheduling Snapshots - BUI, CLI

• Setting a Scheduled Snapshot Label - BUI, CLI

You can make clones of a snapshot, which can be useful to create numerous working versions of one share. To make clones, use the following tasks:

• Cloning a Snapshot - BUI, CLI

• Cloning a Clone

• Cloning a Replication Package - BUI, CLI

To determine the relationships between existing snapshots and clones, use the following tasks:

• Viewing Clones of a Snapshot - BUI, CLI

• Viewing a Clone Origin - BUI, CLI

To view and edit existing snapshots, snapshot schedules, and snapshot retention policies, use the following tasks:

• Viewing Snapshots and Schedules - BUI, CLI

• Renaming a Snapshot - BUI, CLI

• Editing a Snapshot Retention Policy - BUI, CLI

You can look at the contents of filesystem snapshots through the .zfs/snapshot filesystem directory. LUN snapshots cannot be accessed directly, though they can be used as a rollback target or as the source of a clone. To manage and access the .zfs/snapshot directory, use the following tasks:

• Making a Filesystem Snapshot Directory Visible - BUI, CLI

• Accessing a Hidden Filesystem Snapshot Directory (CLI)

• Accessing a Visible Filesystem Snapshot Directory (CLI)

You can use an existing snapshot to restore a filesystem or LUN to the exact state it was in when the snapshot was taken. To roll back a filesystem, LUN, or project to an existing snapshot, use the following task: Rolling Back to a Snapshot - BUI, CLI.

To destroy snapshots, use the following task: Destroying a Snapshot - BUI, CLI.