Creating snapshots
The snapshot create command quickly creates a persistent image of a file system at an exact point in time. Snapshots minimize the use of disk space by using a Storage Checkpoint within the same free space available to the file system. After you create a snapshot of a mounted file system, you can also continue to create, remove, and update files on the file system without affecting the logical image of the snapshot. A snapshot preserves not only the name space (directory hierarchy) of the file system, but also the user data as it existed at the moment the file system image was captured.
You can use a snapshot in many ways. For example, you can use them to:
Create a stable image of the file system that can be backed up to tape.
Provide a mounted, on-disk backup of the file system so that end users can restore their own files in the event of accidental deletion. This is especially useful in a home directory, engineering, or email environment.
Create an on-disk backup of the file system that can be used in addition to a traditional tape-based backup to provide faster backup and restore capabilities.
To create a snapshot
- To create a snapshot, enter the following:
Storage> snapshot create snapshot_name fs_name [removable] <worm> <retention_period>
If the file system is not WORM-enabled, the snapshot cannot be WORM-enabled. Retention period can be set only if the snapshot is WORM-enabled.
snapshot_name
Specifies the name for the snapshot.
Note:
The following are reserved words for snapshot name: flags, ctime, and mtime.
fs_name
Specifies the name for the file system.
removable
Valid values are:
yes
no
If the removable attribute is yes, the snapshot is removed automatically if the file system runs out of space.
The default value is removable=no.
worm
Enables WORM. The possible values are worm=yes/no. Default value of this parameter is no.
retention_period
Specifies the retention period. The format can be [1-9](d|D|m|M|y|Y) or yyyy-mm-dd.