ZFS-SNAPSHOT(8) System Manager's Manual ZFS-SNAPSHOT(8)

zfs-snapshotcreate snapshots of ZFS datasets

zfs snapshot [-r] [-o property=value]… dataset@snapname

Creates a snapshot of a dataset or multiple snapshots of different datasets.

Snapshots are created atomically. That is, a snapshot is a consistent image of a dataset at a specific point in time; it includes all modifications to the dataset made by system calls that have successfully completed before that point in time. Recursive snapshots created through the -r option are all created at the same time.

zfs snap can be used as an alias for zfs snapshot.

See the Snapshots section of zfsconcepts(7) for details.

Set the specified property; see zfs create for details.
Recursively create snapshots of all descendent datasets

The following command creates a snapshot named yesterday. This snapshot is mounted on demand in the .zfs/snapshot directory at the root of the pool/home/bob file system.

# zfs snapshot pool/home/bob@yesterday

The following command creates snapshots named yesterday of pool/home and all of its descendent file systems. Each snapshot is mounted on demand in the .zfs/snapshot directory at the root of its file system. The second command destroys the newly created snapshots.

# zfs snapshot -r pool/home@yesterday
# zfs destroy -r pool/home@yesterday

The following commands illustrate how to test out changes to a file system, and then replace the original file system with the changed one, using clones, clone promotion, and renaming:

# zfs create pool/project/production
  populate /pool/project/production with data
# zfs snapshot pool/project/production@today
# zfs clone pool/project/production@today pool/project/beta
  make changes to /pool/project/beta and test them
# zfs promote pool/project/beta
# zfs rename pool/project/production pool/project/legacy
# zfs rename pool/project/beta pool/project/production
  once the legacy version is no longer needed, it can be destroyed
# zfs destroy pool/project/legacy

The following example shows how to maintain a history of snapshots with a consistent naming scheme. To keep a week's worth of snapshots, the user destroys the oldest snapshot, renames the remaining snapshots, and then creates a new snapshot, as follows:

# zfs destroy -r pool/users@7daysago
# zfs rename -r pool/users@6daysago @7daysago
# zfs rename -r pool/users@5daysago @6daysago
# zfs rename -r pool/users@4daysago @5daysago
# zfs rename -r pool/users@3daysago @4daysago
# zfs rename -r pool/users@2daysago @3daysago
# zfs rename -r pool/users@yesterday @2daysago
# zfs rename -r pool/users@today @yesterday
# zfs snapshot -r pool/users@today

zfs-bookmark(8), zfs-clone(8), zfs-destroy(8), zfs-diff(8), zfs-hold(8), zfs-rename(8), zfs-rollback(8), zfs-send(8)

March 16, 2022 Debian