1SYSTEMD.MOUNT(5)                 systemd.mount                SYSTEMD.MOUNT(5)
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3
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NAME

6       systemd.mount - Mount unit configuration
7

SYNOPSIS

9       mount.mount
10

DESCRIPTION

12       A unit configuration file whose name ends in ".mount" encodes
13       information about a file system mount point controlled and supervised
14       by systemd.
15
16       This man page lists the configuration options specific to this unit
17       type. See systemd.unit(5) for the common options of all unit
18       configuration files. The common configuration items are configured in
19       the generic [Unit] and [Install] sections. The mount specific
20       configuration options are configured in the [Mount] section.
21
22       Additional options are listed in systemd.exec(5), which define the
23       execution environment the mount(8) program is executed in, and in
24       systemd.kill(5), which define the way the processes are terminated, and
25       in systemd.resource-control(5), which configure resource control
26       settings for the processes of the service.
27
28       Note that the options User= and Group= are not useful for mount units.
29       systemd passes two parameters to mount(8); the values of What= and
30       Where=. When invoked in this way, mount(8) does not read any options
31       from /etc/fstab, and must be run as UID 0.
32
33       Mount units must be named after the mount point directories they
34       control. Example: the mount point /home/lennart must be configured in a
35       unit file home-lennart.mount. For details about the escaping logic used
36       to convert a file system path to a unit name, see systemd.unit(5). Note
37       that mount units cannot be templated, nor is possible to add multiple
38       names to a mount unit by creating additional symlinks to it.
39
40       Optionally, a mount unit may be accompanied by an automount unit, to
41       allow on-demand or parallelized mounting. See systemd.automount(5).
42
43       Mount points created at runtime (independently of unit files or
44       /etc/fstab) will be monitored by systemd and appear like any other
45       mount unit in systemd. See /proc/self/mountinfo description in proc(5).
46
47       Some file systems have special semantics as API file systems for
48       kernel-to-userspace and userspace-to-userspace interfaces. Some of them
49       may not be changed via mount units, and cannot be disabled. For a
50       longer discussion see API File Systems[1].
51
52       The systemd-mount(1) command allows creating .mount and .automount
53       units dynamically and transiently from the command line.
54

AUTOMATIC DEPENDENCIES

56   Implicit Dependencies
57       The following dependencies are implicitly added:
58
59       ·   If a mount unit is beneath another mount unit in the file system
60           hierarchy, both a requirement dependency and an ordering dependency
61           between both units are created automatically.
62
63       ·   Block device backed file systems automatically gain BindsTo= and
64           After= type dependencies on the device unit encapsulating the block
65           device (see below).
66
67       ·   If traditional file system quota is enabled for a mount unit,
68           automatic Wants= and Before= dependencies on
69           systemd-quotacheck.service and quotaon.service are added.
70
71       ·   Additional implicit dependencies may be added as result of
72           execution and resource control parameters as documented in
73           systemd.exec(5) and systemd.resource-control(5).
74
75   Default Dependencies
76       The following dependencies are added unless DefaultDependencies=no is
77       set:
78
79       ·   All mount units acquire automatic Before= and Conflicts= on
80           umount.target in order to be stopped during shutdown.
81
82       ·   Mount units referring to local file systems automatically gain an
83           After= dependency on local-fs-pre.target, and a Before= dependency
84           on local-fs.target unless nofail mount option is set.
85
86       ·   Network mount units automatically acquire After= dependencies on
87           remote-fs-pre.target, network.target and network-online.target, and
88           gain a Before= dependency on remote-fs.target unless nofail mount
89           option is set. Towards the latter a Wants= unit is added as well.
90
91       Mount units referring to local and network file systems are
92       distinguished by their file system type specification. In some cases
93       this is not sufficient (for example network block device based mounts,
94       such as iSCSI), in which case _netdev may be added to the mount option
95       string of the unit, which forces systemd to consider the mount unit a
96       network mount.
97

FSTAB

99       Mount units may either be configured via unit files, or via /etc/fstab
100       (see fstab(5) for details). Mounts listed in /etc/fstab will be
101       converted into native units dynamically at boot and when the
102       configuration of the system manager is reloaded. In general,
103       configuring mount points through /etc/fstab is the preferred approach.
104       See systemd-fstab-generator(8) for details about the conversion.
105
106       The NFS mount option bg for NFS background mounts as documented in
107       nfs(5) is detected by systemd-fstab-generator and the options are
108       transformed so that systemd fulfills the job-control implications of
109       that option. Specifically systemd-fstab-generator acts as though
110       "x-systemd.mount-timeout=infinity,retry=10000" was prepended to the
111       option list, and "fg,nofail" was appended. Depending on specific
112       requirements, it may be appropriate to provide some of these options
113       explicitly, or to make use of the "x-systemd.automount" option
114       described below instead of using "bg".
115
116       When reading /etc/fstab a few special mount options are understood by
117       systemd which influence how dependencies are created for mount points.
118       systemd will create a dependency of type Wants= or Requires= (see
119       option nofail below), from either local-fs.target or remote-fs.target,
120       depending whether the file system is local or remote.
121
122       x-systemd.requires=
123           Configures a Requires= and an After= dependency between the created
124           mount unit and another systemd unit, such as a device or mount
125           unit. The argument should be a unit name, or an absolute path to a
126           device node or mount point. This option may be specified more than
127           once. This option is particularly useful for mount point
128           declarations that need an additional device to be around (such as
129           an external journal device for journal file systems) or an
130           additional mount to be in place (such as an overlay file system
131           that merges multiple mount points). See After= and Requires= in
132           systemd.unit(5) for details.
133
134           Note that this option always applies to the created mount unit only
135           regardless whether x-systemd.automount has been specified.
136
137       x-systemd.before=, x-systemd.after=
138           In the created mount unit, configures a Before= or After=
139           dependency on another systemd unit, such as a mount unit. The
140           argument should be a unit name or an absolute path to a mount
141           point. This option may be specified more than once. This option is
142           particularly useful for mount point declarations with nofail option
143           that are mounted asynchronously but need to be mounted before or
144           after some unit start, for example, before local-fs.target unit.
145           See Before= and After= in systemd.unit(5) for details.
146
147           Note that these options always apply to the created mount unit only
148           regardless whether x-systemd.automount has been specified.
149
150       x-systemd.wanted-by=, x-systemd.required-by=
151           In the created mount unit, configures a WantedBy= or RequiredBy=
152           dependency on another unit. This option may be specified more than
153           once. If this is specified, the normal automatic dependencies on
154           the created mount unit, e.g., local-fs.target, are not
155           automatically created. See WantedBy= and RequiredBy= in
156           systemd.unit(5) for details.
157
158       x-systemd.requires-mounts-for=
159           Configures a RequiresMountsFor= dependency between the created
160           mount unit and other mount units. The argument must be an absolute
161           path. This option may be specified more than once. See
162           RequiresMountsFor= in systemd.unit(5) for details.
163
164       x-systemd.device-bound
165           The block device backed file system will be upgraded to BindsTo=
166           dependency. This option is only useful when mounting file systems
167           manually with mount(8) as the default dependency in this case is
168           Requires=. This option is already implied by entries in /etc/fstab
169           or by mount units.
170
171       x-systemd.automount
172           An automount unit will be created for the file system. See
173           systemd.automount(5) for details.
174
175       x-systemd.idle-timeout=
176           Configures the idle timeout of the automount unit. See
177           TimeoutIdleSec= in systemd.automount(5) for details.
178
179       x-systemd.device-timeout=
180           Configure how long systemd should wait for a device to show up
181           before giving up on an entry from /etc/fstab. Specify a time in
182           seconds or explicitly append a unit such as "s", "min", "h", "ms".
183
184           Note that this option can only be used in /etc/fstab, and will be
185           ignored when part of the Options= setting in a unit file.
186
187       x-systemd.mount-timeout=
188           Configure how long systemd should wait for the mount command to
189           finish before giving up on an entry from /etc/fstab. Specify a time
190           in seconds or explicitly append a unit such as "s", "min", "h",
191           "ms".
192
193           Note that this option can only be used in /etc/fstab, and will be
194           ignored when part of the Options= setting in a unit file.
195
196           See TimeoutSec= below for details.
197
198       x-systemd.makefs
199           The file system will be initialized on the device. If the device is
200           not "empty", i.e. it contains any signature, the operation will be
201           skipped. It is hence expected that this option remains set even
202           after the device has been initialized.
203
204           Note that this option can only be used in /etc/fstab, and will be
205           ignored when part of the Options= setting in a unit file.
206
207           See systemd-makefs@.service(8).
208
209           wipefs(8) may be used to remove any signatures from a block device
210           to force x-systemd.makefs to reinitialize the device.
211
212       x-systemd.growfs
213           The file system will be grown to occupy the full block device. If
214           the file system is already at maximum size, no action will be
215           performed. It is hence expected that this option remains set even
216           after the file system has been grown. Only certain file system
217           types are supported, see systemd-makefs@.service(8) for details.
218
219           Note that this option can only be used in /etc/fstab, and will be
220           ignored when part of the Options= setting in a unit file.
221
222       x-systemd.rw-only
223           If a mount operation fails to mount the file system read-write, it
224           normally tries mounting the file system read-only instead. This
225           option disables that behaviour, and causes the mount to fail
226           immediately instead. This option is translated into the
227           ReadWriteOnly= setting in a unit file.
228
229       _netdev
230           Normally the file system type is used to determine if a mount is a
231           "network mount", i.e. if it should only be started after the
232           network is available. Using this option overrides this detection
233           and specifies that the mount requires network.
234
235           Network mount units are ordered between remote-fs-pre.target and
236           remote-fs.target, instead of local-fs-pre.target and
237           local-fs.target. They also pull in network-online.target and are
238           ordered after it and network.target.
239
240       noauto, auto
241           With noauto, the mount unit will not be added as a dependency for
242           local-fs.target or remote-fs.target. This means that it will not be
243           mounted automatically during boot, unless it is pulled in by some
244           other unit. The auto option has the opposite meaning and is the
245           default. Note that the noauto option has an effect on the mount
246           unit itself only — if x-systemd.automount is used (see above), then
247           the matching automount unit will still be pulled in by these
248           targets.
249
250       nofail
251           With nofail, this mount will be only wanted, not required, by
252           local-fs.target or remote-fs.target. Moreover the mount unit is not
253           ordered before these target units. This means that the boot will
254           continue without waiting for the mount unit and regardless whether
255           the mount point can be mounted successfully.
256
257       x-initrd.mount
258           An additional filesystem to be mounted in the initramfs. See
259           initrd-fs.target description in systemd.special(7).
260
261       If a mount point is configured in both /etc/fstab and a unit file that
262       is stored below /usr, the former will take precedence. If the unit file
263       is stored below /etc, it will take precedence. This means: native unit
264       files take precedence over traditional configuration files, but this is
265       superseded by the rule that configuration in /etc will always take
266       precedence over configuration in /usr.
267

OPTIONS

269       Mount files must include a [Mount] section, which carries information
270       about the file system mount points it supervises. A number of options
271       that may be used in this section are shared with other unit types.
272       These options are documented in systemd.exec(5) and systemd.kill(5).
273       The options specific to the [Mount] section of mount units are the
274       following:
275
276       What=
277           Takes an absolute path of a device node, file or other resource to
278           mount. See mount(8) for details. If this refers to a device node, a
279           dependency on the respective device unit is automatically created.
280           (See systemd.device(5) for more information.) This option is
281           mandatory. Note that the usual specifier expansion is applied to
282           this setting, literal percent characters should hence be written as
283           "%%". If this mount is a bind mount and the specified path does not
284           exist yet it is created as directory.
285
286       Where=
287           Takes an absolute path of a file or directory for the mount point;
288           in particular, the destination cannot be a symbolic link. If the
289           mount point does not exist at the time of mounting, it is created
290           as directory. This string must be reflected in the unit filename.
291           (See above.) This option is mandatory.
292
293       Type=
294           Takes a string for the file system type. See mount(8) for details.
295           This setting is optional.
296
297       Options=
298           Mount options to use when mounting. This takes a comma-separated
299           list of options. This setting is optional. Note that the usual
300           specifier expansion is applied to this setting, literal percent
301           characters should hence be written as "%%".
302
303       SloppyOptions=
304           Takes a boolean argument. If true, parsing of the options specified
305           in Options= is relaxed, and unknown mount options are tolerated.
306           This corresponds with mount(8)'s -s switch. Defaults to off.
307
308       LazyUnmount=
309           Takes a boolean argument. If true, detach the filesystem from the
310           filesystem hierarchy at time of the unmount operation, and clean up
311           all references to the filesystem as soon as they are not busy
312           anymore. This corresponds with umount(8)'s -l switch. Defaults to
313           off.
314
315       ReadWriteOnly=
316           Takes a boolean argument. If false, a mount point that shall be
317           mounted read-write but cannot be mounted so is retried to be
318           mounted read-only. If true the operation will fail immediately
319           after the read-write mount attempt did not succeed. This
320           corresponds with mount(8)'s -w switch. Defaults to off.
321
322       ForceUnmount=
323           Takes a boolean argument. If true, force an unmount (in case of an
324           unreachable NFS system). This corresponds with umount(8)'s -f
325           switch. Defaults to off.
326
327       DirectoryMode=
328           Directories of mount points (and any parent directories) are
329           automatically created if needed. This option specifies the file
330           system access mode used when creating these directories. Takes an
331           access mode in octal notation. Defaults to 0755.
332
333       TimeoutSec=
334           Configures the time to wait for the mount command to finish. If a
335           command does not exit within the configured time, the mount will be
336           considered failed and be shut down again. All commands still
337           running will be terminated forcibly via SIGTERM, and after another
338           delay of this time with SIGKILL. (See KillMode= in
339           systemd.kill(5).) Takes a unit-less value in seconds, or a time
340           span value such as "5min 20s". Pass 0 to disable the timeout logic.
341           The default value is set from DefaultTimeoutStartSec= option in
342           systemd-system.conf(5).
343
344       Check systemd.exec(5) and systemd.kill(5) for more settings.
345

SEE ALSO

347       systemd(1), systemctl(1), systemd-system.conf(5), systemd.unit(5),
348       systemd.exec(5), systemd.kill(5), systemd.resource-control(5),
349       systemd.service(5), systemd.device(5), proc(5), mount(8), systemd-
350       fstab-generator(8), systemd.directives(7), systemd-mount(1)
351

NOTES

353        1. API File Systems
354           https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
355
356
357
358systemd 246                                                   SYSTEMD.MOUNT(5)
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