xref: /freebsd/sys/contrib/openzfs/man/man8/zfs-mount-generator.8.in (revision 4b15965daa99044daf184221b7c283bf7f2d7e66)
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26.Dd May 31, 2021
27.Dt ZFS-MOUNT-GENERATOR 8
28.Os
29.
30.Sh NAME
31.Nm zfs-mount-generator
32.Nd generate systemd mount units for ZFS filesystems
33.Sh SYNOPSIS
34.Pa @systemdgeneratordir@/zfs-mount-generator
35.
36.Sh DESCRIPTION
37.Nm
38is a
39.Xr systemd.generator 7
40that generates native
41.Xr systemd.mount 5
42units for configured ZFS datasets.
43.
44.Ss Properties
45.Bl -tag -compact -width "org.openzfs.systemd:required-by=unit[ unit]…"
46.It Sy mountpoint Ns =
47.No Skipped if Sy legacy No or Sy none .
48.
49.It Sy canmount Ns =
50.No Skipped if Sy off .
51.No Skipped if only Sy noauto
52datasets exist for a given mountpoint and there's more than one.
53.No Datasets with Sy yes No take precedence over ones with Sy noauto No for the same mountpoint .
54.No Sets logical Em noauto No flag if Sy noauto .
55Encryption roots always generate
56.Sy zfs-load-key@ Ns Ar root Ns Sy .service ,
57even if
58.Sy off .
59.
60.It Sy atime Ns = , Sy relatime Ns = , Sy devices Ns = , Sy exec Ns = , Sy readonly Ns = , Sy setuid Ns = , Sy nbmand Ns =
61Used to generate mount options equivalent to
62.Nm zfs Cm mount .
63.
64.It Sy encroot Ns = , Sy keylocation Ns =
65If the dataset is an encryption root, its mount unit will bind to
66.Sy zfs-load-key@ Ns Ar root Ns Sy .service ,
67with additional dependencies as follows:
68.Bl -tag -compact -offset Ds -width "keylocation=https://URL (et al.)"
69.It Sy keylocation Ns = Ns Sy prompt
70None, uses
71.Xr systemd-ask-password 1
72.It Sy keylocation Ns = Ns Sy https:// Ns Ar URL Pq et al.\&
73.Sy Wants Ns = , Sy After Ns = : Pa network-online.target
74.It Sy keylocation Ns = Ns Sy file:// Ns < Ns Ar path Ns >
75.Sy RequiresMountsFor Ns = Ns Ar path
76.El
77.
78The service also uses the same
79.Sy Wants Ns = ,
80.Sy After Ns = ,
81.Sy Requires Ns = , No and
82.Sy RequiresMountsFor Ns = ,
83as the mount unit.
84.
85.It Sy org.openzfs.systemd:requires Ns = Ns Pa path Ns Oo " " Ns Pa path Oc Ns …
86.No Sets Sy Requires Ns = for the mount- and key-loading unit.
87.
88.It Sy org.openzfs.systemd:requires-mounts-for Ns = Ns Pa path Ns Oo " " Ns Pa path Oc Ns …
89.No Sets Sy RequiresMountsFor Ns = for the mount- and key-loading unit.
90.
91.It Sy org.openzfs.systemd:before Ns = Ns Pa unit Ns Oo " " Ns Pa unit Oc Ns …
92.No Sets Sy Before Ns = for the mount unit.
93.
94.It Sy org.openzfs.systemd:after Ns = Ns Pa unit Ns Oo " " Ns Pa unit Oc Ns …
95.No Sets Sy After Ns = for the mount unit.
96.
97.It Sy org.openzfs.systemd:wanted-by Ns = Ns Pa unit Ns Oo " " Ns Pa unit Oc Ns …
98.No Sets logical Em noauto No flag (see below) .
99.No If not Sy none , No sets Sy WantedBy Ns = for the mount unit.
100.It Sy org.openzfs.systemd:required-by Ns = Ns Pa unit Ns Oo " " Ns Pa unit Oc Ns …
101.No Sets logical Em noauto No flag (see below) .
102.No If not Sy none , No sets Sy RequiredBy Ns = for the mount unit.
103.
104.It Sy org.openzfs.systemd:nofail Ns = Ns (unset) Ns | Ns Sy on Ns | Ns Sy off
105Waxes or wanes strength of default reverse dependencies of the mount unit, see
106below.
107.
108.It Sy org.openzfs.systemd:ignore Ns = Ns Sy on Ns | Ns Sy off
109.No Skip if Sy on .
110.No Defaults to Sy off .
111.El
112.
113.Ss Unit Ordering And Dependencies
114Additionally, unless the pool the dataset resides on
115is imported at generation time, both units gain
116.Sy Wants Ns = Ns Pa zfs-import.target
117and
118.Sy After Ns = Ns Pa zfs-import.target .
119.Pp
120Additionally, unless the logical
121.Em noauto
122flag is set, the mount unit gains a reverse-dependency for
123.Pa local-fs.target
124of strength
125.Bl -tag -compact -offset Ds -width "(unset)"
126.It (unset)
127.Sy WantedBy Ns = No + Sy Before Ns =
128.It Sy on
129.Sy WantedBy Ns =
130.It Sy off
131.Sy RequiredBy Ns = No + Sy Before Ns =
132.El
133.
134.Ss Cache File
135Because ZFS pools may not be available very early in the boot process,
136information on ZFS mountpoints must be stored separately.
137The output of
138.Dl Nm zfs Cm list Fl Ho Ar name , Ns Aq every property above in order
139for datasets that should be mounted by systemd should be kept at
140.Pa @sysconfdir@/zfs/zfs-list.cache/ Ns Ar poolname ,
141and, if writeable, will be kept synchronized for the entire pool by the
142.Pa history_event-zfs-list-cacher.sh
143ZEDLET, if enabled
144.Pq see Xr zed 8 .
145.
146.Sh ENVIRONMENT
147If the
148.Sy ZFS_DEBUG
149environment variable is nonzero
150.Pq or unset and Pa /proc/cmdline No contains Qq Sy debug ,
151print summary accounting information at the end.
152.
153.Sh EXAMPLES
154To begin, enable tracking for the pool:
155.Dl # Nm touch Pa @sysconfdir@/zfs/zfs-list.cache/ Ns Ar poolname
156Then enable the tracking ZEDLET:
157.Dl # Nm ln Fl s Pa @zfsexecdir@/zed.d/history_event-zfs-list-cacher.sh @sysconfdir@/zfs/zed.d
158.Dl # Nm systemctl Cm enable Pa zfs-zed.service
159.Dl # Nm systemctl Cm restart Pa zfs-zed.service
160.Pp
161If no history event is in the queue,
162inject one to ensure the ZEDLET runs to refresh the cache file
163by setting a monitored property somewhere on the pool:
164.Dl # Nm zfs Cm set Sy relatime Ns = Ns Sy off Ar poolname/dset
165.Dl # Nm zfs Cm inherit Sy relatime Ar poolname/dset
166.Pp
167To test the generator output:
168.Dl $ Nm mkdir Pa /tmp/zfs-mount-generator
169.Dl $ Nm @systemdgeneratordir@/zfs-mount-generator Pa /tmp/zfs-mount-generator
170.
171If the generated units are satisfactory, instruct
172.Nm systemd
173to re-run all generators:
174.Dl # Nm systemctl daemon-reload
175.
176.Sh SEE ALSO
177.Xr systemd.mount 5 ,
178.Xr systemd.target 5 ,
179.Xr zfs 5 ,
180.Xr systemd.generator 7 ,
181.Xr systemd.special 7 ,
182.Xr zed 8 ,
183.Xr zpool-events 8
184