xref: /freebsd/sys/contrib/openzfs/man/man8/zfs-snapshot.8 (revision 9d54812421274e490dc5f0fe4722ab8d35d9b258)
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21.\" Copyright (c) 2009 Sun Microsystems, Inc. All Rights Reserved.
22.\" Copyright 2011 Joshua M. Clulow <josh@sysmgr.org>
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32.Dd March 16, 2022
33.Dt ZFS-SNAPSHOT 8
34.Os
35.
36.Sh NAME
37.Nm zfs-snapshot
38.Nd create snapshots of ZFS datasets
39.Sh SYNOPSIS
40.Nm zfs
41.Cm snapshot
42.Op Fl r
43.Oo Fl o Ar property Ns = Ns Ar value Oc Ns …
44.Ar dataset Ns @ Ns Ar snapname Ns …
45.
46.Sh DESCRIPTION
47All previous modifications by successful system calls to the file system are
48part of the snapshots.
49Snapshots are taken atomically, so that all snapshots correspond to the same
50moment in time.
51.Nm zfs Cm snap
52can be used as an alias for
53.Nm zfs Cm snapshot .
54See the
55.Sx Snapshots
56section of
57.Xr zfsconcepts 7
58for details.
59.Bl -tag -width "-o"
60.It Fl o Ar property Ns = Ns Ar value
61Set the specified property; see
62.Nm zfs Cm create
63for details.
64.It Fl r
65Recursively create snapshots of all descendent datasets
66.El
67.
68.Sh EXAMPLES
69.\" These are, respectively, examples 2, 3, 10, 15 from zfs.8
70.\" Make sure to update them bidirectionally
71.Ss Example 1 : No Creating a ZFS Snapshot
72The following command creates a snapshot named
73.Ar yesterday .
74This snapshot is mounted on demand in the
75.Pa .zfs/snapshot
76directory at the root of the
77.Ar pool/home/bob
78file system.
79.Dl # Nm zfs Cm snapshot Ar pool/home/bob Ns @ Ns Ar yesterday
80.
81.Ss Example 2 : No Creating and Destroying Multiple Snapshots
82The following command creates snapshots named
83.Ar yesterday No of Ar pool/home
84and all of its descendent file systems.
85Each snapshot is mounted on demand in the
86.Pa .zfs/snapshot
87directory at the root of its file system.
88The second command destroys the newly created snapshots.
89.Dl # Nm zfs Cm snapshot Fl r Ar pool/home Ns @ Ns Ar yesterday
90.Dl # Nm zfs Cm destroy Fl r Ar pool/home Ns @ Ns Ar yesterday
91.
92.Ss Example 3 : No Promoting a ZFS Clone
93The following commands illustrate how to test out changes to a file system, and
94then replace the original file system with the changed one, using clones, clone
95promotion, and renaming:
96.Bd -literal -compact -offset Ds
97.No # Nm zfs Cm create Ar pool/project/production
98  populate /pool/project/production with data
99.No # Nm zfs Cm snapshot Ar pool/project/production Ns @ Ns Ar today
100.No # Nm zfs Cm clone Ar pool/project/production@today pool/project/beta
101  make changes to /pool/project/beta and test them
102.No # Nm zfs Cm promote Ar pool/project/beta
103.No # Nm zfs Cm rename Ar pool/project/production pool/project/legacy
104.No # Nm zfs Cm rename Ar pool/project/beta pool/project/production
105  once the legacy version is no longer needed, it can be destroyed
106.No # Nm zfs Cm destroy Ar pool/project/legacy
107.Ed
108.
109.Ss Example 4 : No Performing a Rolling Snapshot
110The following example shows how to maintain a history of snapshots with a
111consistent naming scheme.
112To keep a week's worth of snapshots, the user destroys the oldest snapshot,
113renames the remaining snapshots, and then creates a new snapshot, as follows:
114.Bd -literal -compact -offset Ds
115.No # Nm zfs Cm destroy Fl r Ar pool/users@7daysago
116.No # Nm zfs Cm rename Fl r Ar pool/users@6daysago No @ Ns Ar 7daysago
117.No # Nm zfs Cm rename Fl r Ar pool/users@5daysago No @ Ns Ar 6daysago
118.No # Nm zfs Cm rename Fl r Ar pool/users@4daysago No @ Ns Ar 5daysago
119.No # Nm zfs Cm rename Fl r Ar pool/users@3daysago No @ Ns Ar 4daysago
120.No # Nm zfs Cm rename Fl r Ar pool/users@2daysago No @ Ns Ar 3daysago
121.No # Nm zfs Cm rename Fl r Ar pool/users@yesterday No @ Ns Ar 2daysago
122.No # Nm zfs Cm rename Fl r Ar pool/users@today No @ Ns Ar yesterday
123.No # Nm zfs Cm snapshot Fl r Ar pool/users Ns @ Ns Ar today
124.Ed
125.
126.Sh SEE ALSO
127.Xr zfs-bookmark 8 ,
128.Xr zfs-clone 8 ,
129.Xr zfs-destroy 8 ,
130.Xr zfs-diff 8 ,
131.Xr zfs-hold 8 ,
132.Xr zfs-rename 8 ,
133.Xr zfs-rollback 8 ,
134.Xr zfs-send 8
135