summaryrefslogtreecommitdiffstats
path: root/man/systemd.mount.xml
blob: 9c6c2140961a67a81dfbcb201c06fb4e55462abc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

<refentry id="systemd.mount" xmlns:xi="http://www.w3.org/2001/XInclude">
  <refentryinfo>
    <title>systemd.mount</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemd.mount</refentrytitle>
    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemd.mount</refname>
    <refpurpose>Mount unit configuration</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para><filename><replaceable>mount</replaceable>.mount</filename></para>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>A unit configuration file whose name ends in
    <literal>.mount</literal> encodes information about a file system
    mount point controlled and supervised by systemd.</para>

    <para>This man page lists the configuration options specific to
    this unit type. See
    <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    for the common options of all unit configuration files. The common
    configuration items are configured in the generic [Unit] and
    [Install] sections. The mount specific configuration options are
    configured in the [Mount] section.</para>

    <para>Additional options are listed in
    <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
    which define the execution environment the
    <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
    program is executed in, and in
    <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
    which define the way the processes are terminated, and in
    <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
    which configure resource control settings for the processes of the
    service.</para>

    <para>Note that the options <varname>User=</varname> and
    <varname>Group=</varname> are not useful for mount units.
    systemd passes two parameters to
    <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>;
    the values of <varname>What=</varname> and <varname>Where=</varname>.
    When invoked in this way,
    <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
    does not read any options from <filename>/etc/fstab</filename>, and
    must be run as UID 0.</para>

    <para>Mount units must be named after the mount point directories they control. Example: the mount point
    <filename index="false">/home/lennart</filename> must be configured in a unit file
    <filename>home-lennart.mount</filename>.  For details about the escaping logic used to convert a file
    system path to a unit name, see
    <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Note
    that mount units cannot be templated, nor is possible to add multiple names to a mount unit by creating
    symlinks to its unit file.</para>

    <para>Optionally, a mount unit may be accompanied by an automount
    unit, to allow on-demand or parallelized mounting. See
    <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>

    <para>Mount points created at runtime (independently of unit files
    or <filename>/etc/fstab</filename>) will be monitored by systemd
    and appear like any other mount unit in systemd. See
    <filename>/proc/self/mountinfo</filename> description in
    <citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
    </para>

    <para>Some file systems have special semantics as API file systems
    for kernel-to-userspace and userspace-to-userspace interfaces. Some
    of them may not be changed via mount units, and cannot be
    disabled. For a longer discussion see <ulink
    url="https://systemd.io/API_FILE_SYSTEMS">API
    File Systems</ulink>.</para>

    <para>The
    <citerefentry><refentrytitle>systemd-mount</refentrytitle><manvolnum>1</manvolnum></citerefentry> command
    allows creating <filename>.mount</filename> and <filename>.automount</filename> units dynamically and
    transiently from the command line.</para>
  </refsect1>

  <refsect1>
    <title>Automatic Dependencies</title>

    <refsect2>
      <title>Implicit Dependencies</title>

      <para>The following dependencies are implicitly added:</para>

      <itemizedlist>
        <listitem><para>If a mount unit is beneath another mount unit in the file
        system hierarchy, both a requirement dependency and an ordering
        dependency between both units are created automatically.</para></listitem>

        <listitem><para>Block device backed file systems automatically gain <varname>Requires=</varname>,
        <varname>StopPropagatedFrom=</varname>, and <varname>After=</varname> type dependencies on the
        device unit encapsulating the block device (see <varname>x-systemd.device-bound=</varname> for details).
        </para></listitem>

        <listitem><para>If traditional file system quota is enabled for a mount unit, automatic
        <varname>Wants=</varname> and <varname>Before=</varname> dependencies on
        <filename>systemd-quotacheck.service</filename> and <filename>quotaon.service</filename>
        are added.</para></listitem>

        <listitem><para>Additional implicit dependencies may be added as result of execution and
        resource control parameters as documented in
        <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        and
        <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
        </para></listitem>
      </itemizedlist>
    </refsect2>

    <refsect2>
      <title>Default Dependencies</title>

      <para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>

      <itemizedlist>
        <listitem><para>All mount units acquire automatic <varname>Before=</varname> and <varname>Conflicts=</varname> on
        <filename>umount.target</filename> in order to be stopped during shutdown.</para></listitem>

        <listitem><para>Mount units referring to local file systems automatically gain
        an <varname>After=</varname> dependency on <filename>local-fs-pre.target</filename>, and a
        <varname>Before=</varname> dependency on <filename>local-fs.target</filename> unless one or more
        mount options among <option>nofail</option>, <option>x-systemd.wanted-by=</option>,
        and <option>x-systemd.required-by=</option> is set. See below for detailed information.</para>

        <para>Additionally, an <varname>After=</varname> dependency on <filename>swap.target</filename>
        is added when the file system type is <literal>tmpfs</literal>.</para>
        </listitem>

        <listitem><para>Network mount units automatically acquire <varname>After=</varname> dependencies on
        <filename>remote-fs-pre.target</filename>, <filename>network.target</filename>,
        plus <varname>After=</varname> and <varname>Wants=</varname> dependencies on <filename>network-online.target</filename>,
        and a <varname>Before=</varname> dependency on <filename>remote-fs.target</filename>, unless
        one or more mount options among <option>nofail</option>, <option>x-systemd.wanted-by=</option>,
        and <option>x-systemd.required-by=</option> is set.</para></listitem>
      </itemizedlist>

      <para>Mount units referring to local and network file systems are distinguished by their file system type
      specification. In some cases this is not sufficient (for example network block device based mounts, such as
      iSCSI), in which case <option>_netdev</option> may be added to the mount option string of the unit, which forces
      systemd to consider the mount unit a network mount.</para>
    </refsect2>
  </refsect1>

  <refsect1>
    <title><filename>fstab</filename></title>

    <para>Mount units may either be configured via unit files, or via <filename>/etc/fstab</filename> (see
    <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    for details). Mounts listed in <filename>/etc/fstab</filename> will be converted into native units
    dynamically at boot and when the configuration of the system manager is reloaded. In general, configuring
    mount points through <filename>/etc/fstab</filename> is the preferred approach to manage mounts for
    humans. For tooling, writing mount units should be preferred over editing <filename>/etc/fstab</filename>.
    See <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
    for details about the conversion from <filename>/etc/fstab</filename> to mount units.</para>

    <para>The NFS mount option <option>bg</option> for NFS background mounts
    as documented in <citerefentry project='man-pages'><refentrytitle>nfs</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    is detected by <command>systemd-fstab-generator</command> and the options
    are transformed so that systemd fulfills the job-control implications of
    that option.  Specifically <command>systemd-fstab-generator</command> acts
    as though <literal>x-systemd.mount-timeout=infinity,retry=10000</literal> was
    prepended to the option list, and <literal>fg,nofail</literal> was appended.
    Depending on specific requirements, it may be appropriate to provide some of
    these options explicitly, or to make use of the
    <literal>x-systemd.automount</literal> option described below instead
    of using <literal>bg</literal>.</para>

    <para>When reading <filename>/etc/fstab</filename> a few special
    mount options are understood by systemd which influence how
    dependencies are created for mount points. systemd will create a
    dependency of type <varname>Wants=</varname> or
    <option>Requires=</option> (see option <option>nofail</option>
    below), from either <filename>local-fs.target</filename> or
    <filename>remote-fs.target</filename>, depending whether the file
    system is local or remote.</para>

    <variablelist class='fstab-options'>

      <varlistentry>
        <term><option>x-systemd.requires=</option></term>

        <listitem><para>Configures a <varname>Requires=</varname> and
        an <varname>After=</varname> dependency between the created
        mount unit and another systemd unit, such as a device or mount
        unit. The argument should be a unit name, or an absolute path
        to a device node or mount point.  This option may be specified
        more than once. This option is particularly useful for mount
        point declarations that need an additional device to be around
        (such as an external journal device for journal file systems)
        or an additional mount to be in place (such as an overlay file
        system that merges multiple mount points). See
        <varname>After=</varname> and <varname>Requires=</varname> in
        <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        for details.</para>

        <para>Note that this option always applies to the created mount unit
        only regardless whether <option>x-systemd.automount</option> has been
        specified.</para>

        <xi:include href="version-info.xml" xpointer="v220"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.wants=</option></term>

        <listitem><para>Configures a <varname>Wants=</varname> and
        an <varname>After=</varname> dependency between the created
        mount unit and another systemd unit, similar to the
        <varname>x-systemd.requires=</varname> option.</para>

        <xi:include href="version-info.xml" xpointer="v257"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.before=</option></term>
        <term><option>x-systemd.after=</option></term>

        <listitem><para>In the created mount unit, configures a
        <varname>Before=</varname> or <varname>After=</varname>
        dependency on another systemd unit, such as a mount unit.
        The argument should be a unit name or an absolute path
        to a mount point. This option may be specified more than once.
        This option is particularly useful for mount point declarations
        with <option>nofail</option> option that are mounted
        asynchronously but need to be mounted before or after some unit
        start, for example, before <filename>local-fs.target</filename>
        unit.
        See <varname>Before=</varname> and <varname>After=</varname> in
        <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        for details.</para>

        <para>Note that these options always apply to the created mount unit
        only regardless whether <option>x-systemd.automount</option> has been
        specified.</para>

        <xi:include href="version-info.xml" xpointer="v233"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.wanted-by=</option></term>
        <term><option>x-systemd.required-by=</option></term>

        <listitem><para>In the created mount unit, configures a <varname>WantedBy=</varname> or
        <varname>RequiredBy=</varname> dependency on another unit. This option may be specified more than once.
        If this is specified, the default dependencies (see above) other than <filename>umount.target</filename>
        on the created mount unit, e.g. <filename>local-fs.target</filename>, are not automatically created.
        Hence it is likely that some ordering dependencies need to be set up manually through
        <option>x-systemd.before=</option> and <option>x-systemd.after=</option>. See <varname>WantedBy=</varname>
        and <varname>RequiredBy=</varname> in
        <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        for details.</para>

        <xi:include href="version-info.xml" xpointer="v245"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.wants-mounts-for=</option></term>
        <term><option>x-systemd.requires-mounts-for=</option></term>

        <listitem><para>Configures a
        <varname>RequiresMountsFor=</varname> or <varname>WantsMountsFor=</varname>
        dependency between the created mount unit and other mount units. The
        argument must be an absolute path. This option may be specified more than
        once. See <varname>RequiresMountsFor=</varname> or <varname>WantsMountsFor=</varname> in
        <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        for details.</para>

        <xi:include href="version-info.xml" xpointer="v220"/></listitem>
       </varlistentry>

      <varlistentry>
        <term><option>x-systemd.device-bound=</option></term>

        <listitem><para>Takes a boolean argument. If true or no argument, a <varname>BindsTo=</varname> dependency
        on the backing device is set. If false, the mount unit is not stopped no matter whether the backing device
        is still present. This is useful when the file system is backed by volume managers. If not set, and the mount
        comes from unit fragments, i.e. generated from <filename>/etc/fstab</filename> by <citerefentry>
        <refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> or loaded from
        a manually configured mount unit, a combination of <varname>Requires=</varname> and <varname>StopPropagatedFrom=</varname>
        dependencies is set on the backing device. If doesn't, only <varname>Requires=</varname> is used.</para>

        <xi:include href="version-info.xml" xpointer="v233"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.automount</option></term>

        <listitem><para>An automount unit will be created for the file
        system. See
        <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        for details.</para>

        <xi:include href="version-info.xml" xpointer="v215"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.idle-timeout=</option></term>

        <listitem><para>Configures the idle timeout of the
        automount unit. See <varname>TimeoutIdleSec=</varname> in
        <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        for details.</para>

        <xi:include href="version-info.xml" xpointer="v220"/></listitem>
      </varlistentry>

      <varlistentry id='device-timeout'>
        <term><option>x-systemd.device-timeout=</option></term>

        <listitem><para>Configure how long systemd should wait for a
        device to show up before giving up on an entry from
        <filename>/etc/fstab</filename>. Specify a time in seconds or
        explicitly append a unit such as <literal>s</literal>,
        <literal>min</literal>, <literal>h</literal>,
        <literal>ms</literal>.</para>

        <para>Note that this option can only be used in
        <filename>/etc/fstab</filename>, and will be
        ignored when part of the <varname>Options=</varname>
        setting in a unit file.</para>

        <xi:include href="version-info.xml" xpointer="v215"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.mount-timeout=</option></term>

        <listitem><para>Configure how long systemd should wait for the
        mount command to finish before giving up on an entry from
        <filename>/etc/fstab</filename>. Specify a time in seconds or
        explicitly append a unit such as <literal>s</literal>,
        <literal>min</literal>, <literal>h</literal>,
        <literal>ms</literal>.</para>

        <para>Note that this option can only be used in
        <filename>/etc/fstab</filename>, and will be
        ignored when part of the <varname>Options=</varname>
        setting in a unit file.</para>

        <para>See <varname>TimeoutSec=</varname> below for
        details.</para>

        <xi:include href="version-info.xml" xpointer="v233"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.makefs</option></term>

        <listitem><para>The file system will be initialized
        on the device. If the device is not "empty", i.e. it contains any signature,
        the operation will be skipped. It is hence expected that this option
        remains set even after the device has been initialized.</para>

        <para>Note that this option can only be used in
        <filename>/etc/fstab</filename>, and will be ignored when part of the
        <varname>Options=</varname> setting in a unit file.</para>

        <para>See
        <citerefentry><refentrytitle>systemd-makefs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
        </para>

        <para><citerefentry project='man-pages'><refentrytitle>wipefs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        may be used to remove any signatures from a block device to force
        <option>x-systemd.makefs</option> to reinitialize the device.</para>

        <xi:include href="version-info.xml" xpointer="v236"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.growfs</option></term>

        <listitem><para>The file system will be grown to occupy the full block
        device. If the file system is already at maximum size, no action will
        be performed. It is hence expected that this option remains set even after
        the file system has been grown. Only certain file system types are supported,
        see
        <citerefentry><refentrytitle>systemd-makefs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        for details.</para>

        <para>Note that this option can only be used in
        <filename>/etc/fstab</filename>, and will be ignored when part of the
        <varname>Options=</varname> setting in a unit file.</para>

        <xi:include href="version-info.xml" xpointer="v236"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.pcrfs</option></term>

        <listitem><para>Measures file system identity information (mount point, type, label, UUID, partition
        label, partition UUID) into PCR 15 after the file system has been mounted. This ensures the
        <citerefentry><refentrytitle>systemd-pcrfs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        or <filename>systemd-pcrfs-root.service</filename> services are pulled in by the mount unit.</para>

        <para>Note that this option can only be used in <filename>/etc/fstab</filename>, and will be ignored
        when part of the <varname>Options=</varname> setting in a unit file. It is also implied for the root
        and <filename>/usr/</filename> partitions discovered by
        <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>

        <xi:include href="version-info.xml" xpointer="v253"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-systemd.rw-only</option></term>

        <listitem><para>If a mount operation fails to mount the file system
        read-write, it normally tries mounting the file system read-only instead.
        This option disables that behaviour, and causes the mount to fail
        immediately instead. This option is translated into the
        <varname>ReadWriteOnly=</varname> setting in a unit file.</para>

        <xi:include href="version-info.xml" xpointer="v246"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>_netdev</option></term>

        <listitem><para>Normally the file system type is used to determine if a
        mount is a "network mount", i.e. if it should only be started after the
        network is available. Using this option overrides this detection and
        specifies that the mount requires network.</para>

        <para>Network mount units are ordered between <filename>remote-fs-pre.target</filename>
        and <filename>remote-fs.target</filename>, instead of
        <filename>local-fs-pre.target</filename> and <filename>local-fs.target</filename>.
        They also pull in <filename>network-online.target</filename> and are ordered after
        it and <filename>network.target</filename>.</para>

        <xi:include href="version-info.xml" xpointer="v235"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>noauto</option></term>
        <term><option>auto</option></term>

        <listitem><para>With <option>noauto</option>, the mount unit will not be added as a dependency for
        <filename>local-fs.target</filename> or <filename>remote-fs.target</filename>. This means that it
        will not be mounted automatically during boot, unless it is pulled in by some other unit. The
        <option>auto</option> option has the opposite meaning and is the default.</para>

        <para>Note that if <option>x-systemd.automount</option> (see above) is used, neither
        <option>auto</option> nor <option>noauto</option> have any effect. The matching automount unit will
        be added as a dependency to the appropriate target.</para>

        <xi:include href="version-info.xml" xpointer="v215"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>nofail</option></term>

        <listitem><para>With <option>nofail</option>, this mount will be only wanted, not required, by
        <filename>local-fs.target</filename> or <filename>remote-fs.target</filename>. Moreover the mount unit is not
        ordered before these target units. This means that the boot will continue without waiting for the mount unit
        and regardless whether the mount point can be mounted successfully.</para>

        <xi:include href="version-info.xml" xpointer="v215"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>x-initrd.mount</option></term>

        <listitem><para>An additional filesystem to be mounted in the initrd. See
        <filename>initrd-fs.target</filename> description in
        <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>. This
        is both an indicator to the initrd to mount this partition early and an indicator to the host to
        leave the partition mounted until final shutdown. Or in other words, if this flag is set it is
        assumed the mount shall be active during the entire regular runtime of the system, i.e. established
        before the initrd transitions into the host all the way until the host transitions to the final
        shutdown phase.</para>

        <xi:include href="version-info.xml" xpointer="v215"/></listitem>
      </varlistentry>
    </variablelist>

    <para>If a mount point is configured in both
    <filename>/etc/fstab</filename> and a unit file that is stored
    below <filename>/usr/</filename>, the former will take precedence.
    If the unit file is stored below <filename>/etc/</filename>, it
    will take precedence. This means: native unit files take
    precedence over traditional configuration files, but this is
    superseded by the rule that configuration in
    <filename>/etc/</filename> will always take precedence over
    configuration in <filename>/usr/</filename>.</para>
  </refsect1>

  <refsect1>
    <title>Options</title>

    <para>Mount unit files may include [Unit] and [Install] sections, which are described in
    <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
    </para>

    <para>Mount unit files must include a [Mount] section, which carries
    information about the file system mount points it supervises. A
    number of options that may be used in this section are shared with
    other unit types. These options are documented in
    <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
    <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry> and
    <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
    The options specific to the [Mount] section of mount units are the
    following:</para>

    <variablelist class='unit-directives'>

      <varlistentry>
        <term><varname>What=</varname></term>
        <listitem><para>Takes an absolute path or a fstab-style identifier of a device node, file or
        other resource to mount. See <citerefentry
        project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
        details. If this refers to a device node, a dependency on the respective device unit is automatically
        created. (See
        <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
        for more information.) This option is mandatory. Note that the usual specifier expansion is applied
        to this setting, literal percent characters should hence be written as <literal
        class='specifiers'>%%</literal>. If this mount is a bind mount and the specified path does not exist
        yet it is created as directory.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>Where=</varname></term>
        <listitem><para>Takes an absolute path of a file or directory for the mount point; in particular, the
        destination cannot be a symbolic link.  If the mount point does not exist at the time of mounting, it
        is created as either a directory or a file. The former is the usual case; the latter is done only if this mount
        is a bind mount and the source (<varname>What=</varname>) is not a directory.
        This string must be reflected in the unit filename. (See above.) This option
        is mandatory.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>Type=</varname></term>
        <listitem><para>Takes a string for the file system type. See
        <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        for details. This setting is optional.</para>

        <para>If the type is <literal>overlay</literal>, and <literal>upperdir=</literal> or
        <literal>workdir=</literal> are specified as options and they don't exist, they will be created.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>Options=</varname></term>

        <listitem><para>Mount options to use when mounting. This takes a comma-separated list of options. This setting
        is optional. Note that the usual specifier expansion is applied to this setting, literal percent characters
        should hence be written as <literal class='specifiers'>%%</literal>.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>SloppyOptions=</varname></term>

        <listitem><para>Takes a boolean argument. If true, parsing of
        the options specified in <varname>Options=</varname> is
        relaxed, and unknown mount options are tolerated. This
        corresponds with
        <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
        <parameter>-s</parameter> switch. Defaults to
        off.</para>

        <xi:include href="version-info.xml" xpointer="v215"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>LazyUnmount=</varname></term>

        <listitem><para>Takes a boolean argument. If true, detach the
        filesystem from the filesystem hierarchy at time of the unmount
        operation, and clean up all references to the filesystem as
        soon as they are not busy anymore.
        This corresponds with
        <citerefentry project='man-pages'><refentrytitle>umount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
        <parameter>-l</parameter> switch. Defaults to
        off.</para>

        <xi:include href="version-info.xml" xpointer="v232"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>ReadWriteOnly=</varname></term>

        <listitem><para>Takes a boolean argument. If false, a mount
        point that shall be mounted read-write but cannot be mounted
        so is retried to be mounted read-only. If true the operation
        will fail immediately after the read-write mount attempt did
        not succeed. This corresponds with
        <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
        <parameter>-w</parameter> switch. Defaults to
        off.</para>

        <xi:include href="version-info.xml" xpointer="v246"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>ForceUnmount=</varname></term>

        <listitem><para>Takes a boolean argument. If true, force an
        unmount (in case of an unreachable NFS system).
        This corresponds with
        <citerefentry project='man-pages'><refentrytitle>umount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
        <parameter>-f</parameter> switch. Defaults to
        off.</para>

        <xi:include href="version-info.xml" xpointer="v232"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>DirectoryMode=</varname></term>
        <listitem><para>Directories of mount points (and any parent
        directories) are automatically created if needed. This option
        specifies the file system access mode used when creating these
        directories. Takes an access mode in octal notation. Defaults
        to 0755.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>TimeoutSec=</varname></term>
        <listitem><para>Configures the time to wait for the mount
        command to finish. If a command does not exit within the
        configured time, the mount will be considered failed and be
        shut down again. All commands still running will be terminated
        forcibly via <constant>SIGTERM</constant>, and after another
        delay of this time with <constant>SIGKILL</constant>. (See
        <option>KillMode=</option> in
        <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
        Takes a unit-less value in seconds, or a time span value such
        as "5min 20s". Pass 0 to disable the timeout logic. The
        default value is set from <varname>DefaultTimeoutStartSec=</varname> option in
        <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
        </para></listitem>
      </varlistentry>
    </variablelist>

    <xi:include href="systemd.service.xml" xpointer="shared-unit-options" />
  </refsect1>

  <refsect1>
      <title>See Also</title>
      <para><simplelist type="inline">
        <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd-mount</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
      </simplelist></para>
  </refsect1>

</refentry>