man/systemd.mount.xml

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   5
   6 <refentry id="systemd.mount" xmlns:xi="http://www.w3.org/2001/XInclude">
   7   <refentryinfo>
   8     <title>systemd.mount</title>
   9     <productname>systemd</productname>
  10   </refentryinfo>
  11
  12   <refmeta>
  13     <refentrytitle>systemd.mount</refentrytitle>
  14     <manvolnum>5</manvolnum>
  15   </refmeta>
  16
  17   <refnamediv>
  18     <refname>systemd.mount</refname>
  19     <refpurpose>Mount unit configuration</refpurpose>
  20   </refnamediv>
  21
  22   <refsynopsisdiv>
  23     <para><filename><replaceable>mount</replaceable>.mount</filename></para>
  24   </refsynopsisdiv>
  25
  26   <refsect1>
  27     <title>Description</title>
  28
  29     <para>A unit configuration file whose name ends in
  30     <literal>.mount</literal> encodes information about a file system
  31     mount point controlled and supervised by systemd.</para>
  32
  33     <para>This man page lists the configuration options specific to
  34     this unit type. See
  35     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  36     for the common options of all unit configuration files. The common
  37     configuration items are configured in the generic [Unit] and
  38     [Install] sections. The mount specific configuration options are
  39     configured in the [Mount] section.</para>
  40
  41     <para>Additional options are listed in
  42     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  43     which define the execution environment the
  44     <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  45     program is executed in, and in
  46     <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  47     which define the way the processes are terminated, and in
  48     <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  49     which configure resource control settings for the processes of the
  50     service.</para>
  51
  52     <para>Note that the options <varname>User=</varname> and
  53     <varname>Group=</varname> are not useful for mount units.
  54     systemd passes two parameters to
  55     <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>;
  56     the values of <varname>What=</varname> and <varname>Where=</varname>.
  57     When invoked in this way,
  58     <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  59     does not read any options from <filename>/etc/fstab</filename>, and
  60     must be run as UID 0.</para>
  61
  62     <para>Mount units must be named after the mount point directories they control. Example: the mount point
  63     <filename index="false">/home/lennart</filename> must be configured in a unit file
  64     <filename>home-lennart.mount</filename>.  For details about the escaping logic used to convert a file
  65     system path to a unit name, see
  66     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Note
  67     that mount units cannot be templated, nor is possible to add multiple names to a mount unit by creating
  68     symlinks to its unit file.</para>
  69
  70     <para>Optionally, a mount unit may be accompanied by an automount
  71     unit, to allow on-demand or parallelized mounting. See
  72     <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
  73
  74     <para>Mount points created at runtime (independently of unit files
  75     or <filename>/etc/fstab</filename>) will be monitored by systemd
  76     and appear like any other mount unit in systemd. See
  77     <filename>/proc/self/mountinfo</filename> description in
  78     <citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
  79     </para>
  80
  81     <para>Some file systems have special semantics as API file systems
  82     for kernel-to-userspace and userspace-to-userspace interfaces. Some
  83     of them may not be changed via mount units, and cannot be
  84     disabled. For a longer discussion see <ulink
  85     url="https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
  86     File Systems</ulink>.</para>
  87
  88     <para>The
  89     <citerefentry><refentrytitle>systemd-mount</refentrytitle><manvolnum>1</manvolnum></citerefentry> command
  90     allows creating <filename>.mount</filename> and <filename>.automount</filename> units dynamically and
  91     transiently from the command line.</para>
  92   </refsect1>
  93
  94   <refsect1>
  95     <title>Automatic Dependencies</title>
  96
  97     <refsect2>
  98       <title>Implicit Dependencies</title>
  99
 100       <para>The following dependencies are implicitly added:</para>
 101
 102       <itemizedlist>
 103         <listitem><para>If a mount unit is beneath another mount unit in the file
 104         system hierarchy, both a requirement dependency and an ordering
 105         dependency between both units are created automatically.</para></listitem>
 106
 107         <listitem><para>Block device backed file systems automatically gain <varname>Requires=</varname>,
 108         <varname>StopPropagatedFrom=</varname>, and <varname>After=</varname> type dependencies on the
 109         device unit encapsulating the block device (see <varname>x-systemd.device-bound=</varname> for details).
 110         </para></listitem>
 111
 112         <listitem><para>If traditional file system quota is enabled for a mount unit, automatic
 113         <varname>Wants=</varname> and <varname>Before=</varname> dependencies on
 114         <filename>systemd-quotacheck.service</filename> and <filename>quotaon.service</filename>
 115         are added.</para></listitem>
 116
 117         <listitem><para>Additional implicit dependencies may be added as result of execution and
 118         resource control parameters as documented in
 119         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 120         and
 121         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 122         </para></listitem>
 123       </itemizedlist>
 124     </refsect2>
 125
 126     <refsect2>
 127       <title>Default Dependencies</title>
 128
 129       <para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
 130
 131       <itemizedlist>
 132         <listitem><para>All mount units acquire automatic <varname>Before=</varname> and <varname>Conflicts=</varname> on
 133         <filename>umount.target</filename> in order to be stopped during shutdown.</para></listitem>
 134
 135         <listitem><para>Mount units referring to local file systems automatically gain
 136         an <varname>After=</varname> dependency on <filename>local-fs-pre.target</filename>, and a
 137         <varname>Before=</varname> dependency on <filename>local-fs.target</filename> unless one or more
 138         mount options among <option>nofail</option>, <option>x-systemd.wanted-by=</option>,
 139         and <option>x-systemd.required-by=</option> is set. See below for detailed information.</para>
 140
 141         <para>Additionally, an <varname>After=</varname> dependency on <filename>swap.target</filename>
 142         is added when the file system type is <literal>tmpfs</literal>.</para>
 143         </listitem>
 144
 145         <listitem><para>Network mount units automatically acquire <varname>After=</varname> dependencies on
 146         <filename>remote-fs-pre.target</filename>, <filename>network.target</filename>,
 147         plus <varname>After=</varname> and <varname>Wants=</varname> dependencies on <filename>network-online.target</filename>,
 148         and a <varname>Before=</varname> dependency on <filename>remote-fs.target</filename>, unless
 149         one or more mount options among <option>nofail</option>, <option>x-systemd.wanted-by=</option>,
 150         and <option>x-systemd.required-by=</option> is set.</para></listitem>
 151       </itemizedlist>
 152
 153       <para>Mount units referring to local and network file systems are distinguished by their file system type
 154       specification. In some cases this is not sufficient (for example network block device based mounts, such as
 155       iSCSI), in which case <option>_netdev</option> may be added to the mount option string of the unit, which forces
 156       systemd to consider the mount unit a network mount.</para>
 157     </refsect2>
 158   </refsect1>
 159
 160   <refsect1>
 161     <title><filename>fstab</filename></title>
 162
 163     <para>Mount units may either be configured via unit files, or via <filename>/etc/fstab</filename> (see
 164     <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 165     for details). Mounts listed in <filename>/etc/fstab</filename> will be converted into native units
 166     dynamically at boot and when the configuration of the system manager is reloaded. In general, configuring
 167     mount points through <filename>/etc/fstab</filename> is the preferred approach to manage mounts for
 168     humans. For tooling, writing mount units should be preferred over editing <filename>/etc/fstab</filename>.
 169     See <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 170     for details about the conversion from <filename>/etc/fstab</filename> to mount units.</para>
 171
 172     <para>The NFS mount option <option>bg</option> for NFS background mounts
 173     as documented in <citerefentry project='man-pages'><refentrytitle>nfs</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 174     is detected by <command>systemd-fstab-generator</command> and the options
 175     are transformed so that systemd fulfills the job-control implications of
 176     that option.  Specifically <command>systemd-fstab-generator</command> acts
 177     as though <literal>x-systemd.mount-timeout=infinity,retry=10000</literal> was
 178     prepended to the option list, and <literal>fg,nofail</literal> was appended.
 179     Depending on specific requirements, it may be appropriate to provide some of
 180     these options explicitly, or to make use of the
 181     <literal>x-systemd.automount</literal> option described below instead
 182     of using <literal>bg</literal>.</para>
 183
 184     <para>When reading <filename>/etc/fstab</filename> a few special
 185     mount options are understood by systemd which influence how
 186     dependencies are created for mount points. systemd will create a
 187     dependency of type <varname>Wants=</varname> or
 188     <option>Requires=</option> (see option <option>nofail</option>
 189     below), from either <filename>local-fs.target</filename> or
 190     <filename>remote-fs.target</filename>, depending whether the file
 191     system is local or remote.</para>
 192
 193     <variablelist class='fstab-options'>
 194
 195       <varlistentry>
 196         <term><option>x-systemd.requires=</option></term>
 197
 198         <listitem><para>Configures a <varname>Requires=</varname> and
 199         an <varname>After=</varname> dependency between the created
 200         mount unit and another systemd unit, such as a device or mount
 201         unit. The argument should be a unit name, or an absolute path
 202         to a device node or mount point.  This option may be specified
 203         more than once. This option is particularly useful for mount
 204         point declarations that need an additional device to be around
 205         (such as an external journal device for journal file systems)
 206         or an additional mount to be in place (such as an overlay file
 207         system that merges multiple mount points). See
 208         <varname>After=</varname> and <varname>Requires=</varname> in
 209         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 210         for details.</para>
 211
 212         <para>Note that this option always applies to the created mount unit
 213         only regardless whether <option>x-systemd.automount</option> has been
 214         specified.</para>
 215
 216         <xi:include href="version-info.xml" xpointer="v220"/></listitem>
 217       </varlistentry>
 218
 219       <varlistentry>
 220         <term><option>x-systemd.before=</option></term>
 221         <term><option>x-systemd.after=</option></term>
 222
 223         <listitem><para>In the created mount unit, configures a
 224         <varname>Before=</varname> or <varname>After=</varname>
 225         dependency on another systemd unit, such as a mount unit.
 226         The argument should be a unit name or an absolute path
 227         to a mount point. This option may be specified more than once.
 228         This option is particularly useful for mount point declarations
 229         with <option>nofail</option> option that are mounted
 230         asynchronously but need to be mounted before or after some unit
 231         start, for example, before <filename>local-fs.target</filename>
 232         unit.
 233         See <varname>Before=</varname> and <varname>After=</varname> in
 234         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 235         for details.</para>
 236
 237         <para>Note that these options always apply to the created mount unit
 238         only regardless whether <option>x-systemd.automount</option> has been
 239         specified.</para>
 240
 241         <xi:include href="version-info.xml" xpointer="v233"/></listitem>
 242       </varlistentry>
 243
 244       <varlistentry>
 245         <term><option>x-systemd.wanted-by=</option></term>
 246         <term><option>x-systemd.required-by=</option></term>
 247
 248         <listitem><para>In the created mount unit, configures a <varname>WantedBy=</varname> or
 249         <varname>RequiredBy=</varname> dependency on another unit. This option may be specified more than once.
 250         If this is specified, the default dependencies (see above) other than <filename>umount.target</filename>
 251         on the created mount unit, e.g. <filename>local-fs.target</filename>, are not automatically created.
 252         Hence it is likely that some ordering dependencies need to be set up manually through
 253         <option>x-systemd.before=</option> and <option>x-systemd.after=</option>. See <varname>WantedBy=</varname>
 254         and <varname>RequiredBy=</varname> in
 255         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 256         for details.</para>
 257
 258         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 259       </varlistentry>
 260
 261       <varlistentry>
 262         <term><option>x-systemd.wants-mounts-for=</option></term>
 263         <term><option>x-systemd.requires-mounts-for=</option></term>
 264
 265         <listitem><para>Configures a
 266         <varname>RequiresMountsFor=</varname> or <varname>WantsMountsFor=</varname>
 267         dependency between the created mount unit and other mount units. The
 268         argument must be an absolute path. This option may be specified more than
 269         once. See <varname>RequiresMountsFor=</varname> or <varname>WantsMountsFor=</varname> in
 270         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 271         for details.</para>
 272
 273         <xi:include href="version-info.xml" xpointer="v220"/></listitem>
 274        </varlistentry>
 275
 276       <varlistentry>
 277         <term><option>x-systemd.device-bound=</option></term>
 278
 279         <listitem><para>Takes a boolean argument. If true or no argument, a <varname>BindsTo=</varname> dependency
 280         on the backing device is set. If false, the mount unit is not stopped no matter whether the backing device
 281         is still present. This is useful when the file system is backed by volume managers. If not set, and the mount
 282         comes from unit fragments, i.e. generated from <filename>/etc/fstab</filename> by <citerefentry>
 283         <refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> or loaded from
 284         a manually configured mount unit, a combination of <varname>Requires=</varname> and <varname>StopPropagatedFrom=</varname>
 285         dependencies is set on the backing device. If doesn't, only <varname>Requires=</varname> is used.</para>
 286
 287         <xi:include href="version-info.xml" xpointer="v233"/></listitem>
 288       </varlistentry>
 289
 290       <varlistentry>
 291         <term><option>x-systemd.automount</option></term>
 292
 293         <listitem><para>An automount unit will be created for the file
 294         system. See
 295         <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 296         for details.</para>
 297
 298         <xi:include href="version-info.xml" xpointer="v215"/></listitem>
 299       </varlistentry>
 300
 301       <varlistentry>
 302         <term><option>x-systemd.idle-timeout=</option></term>
 303
 304         <listitem><para>Configures the idle timeout of the
 305         automount unit. See <varname>TimeoutIdleSec=</varname> in
 306         <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 307         for details.</para>
 308
 309         <xi:include href="version-info.xml" xpointer="v220"/></listitem>
 310       </varlistentry>
 311
 312       <varlistentry id='device-timeout'>
 313         <term><option>x-systemd.device-timeout=</option></term>
 314
 315         <listitem><para>Configure how long systemd should wait for a
 316         device to show up before giving up on an entry from
 317         <filename>/etc/fstab</filename>. Specify a time in seconds or
 318         explicitly append a unit such as <literal>s</literal>,
 319         <literal>min</literal>, <literal>h</literal>,
 320         <literal>ms</literal>.</para>
 321
 322         <para>Note that this option can only be used in
 323         <filename>/etc/fstab</filename>, and will be
 324         ignored when part of the <varname>Options=</varname>
 325         setting in a unit file.</para>
 326
 327         <xi:include href="version-info.xml" xpointer="v215"/>
 328         </listitem>
 329       </varlistentry>
 330
 331       <varlistentry>
 332         <term><option>x-systemd.mount-timeout=</option></term>
 333
 334         <listitem><para>Configure how long systemd should wait for the
 335         mount command to finish before giving up on an entry from
 336         <filename>/etc/fstab</filename>. Specify a time in seconds or
 337         explicitly append a unit such as <literal>s</literal>,
 338         <literal>min</literal>, <literal>h</literal>,
 339         <literal>ms</literal>.</para>
 340
 341         <para>Note that this option can only be used in
 342         <filename>/etc/fstab</filename>, and will be
 343         ignored when part of the <varname>Options=</varname>
 344         setting in a unit file.</para>
 345
 346         <para>See <varname>TimeoutSec=</varname> below for
 347         details.</para>
 348
 349         <xi:include href="version-info.xml" xpointer="v233"/>
 350         </listitem>
 351       </varlistentry>
 352
 353       <varlistentry>
 354         <term><option>x-systemd.makefs</option></term>
 355
 356         <listitem><para>The file system will be initialized
 357         on the device. If the device is not "empty", i.e. it contains any signature,
 358         the operation will be skipped. It is hence expected that this option
 359         remains set even after the device has been initialized.</para>
 360
 361         <para>Note that this option can only be used in
 362         <filename>/etc/fstab</filename>, and will be ignored when part of the
 363         <varname>Options=</varname> setting in a unit file.</para>
 364
 365         <para>See
 366         <citerefentry><refentrytitle>systemd-makefs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 367         </para>
 368
 369         <para><citerefentry project='man-pages'><refentrytitle>wipefs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 370         may be used to remove any signatures from a block device to force
 371         <option>x-systemd.makefs</option> to reinitialize the device.</para>
 372
 373         <xi:include href="version-info.xml" xpointer="v236"/>
 374         </listitem>
 375       </varlistentry>
 376
 377       <varlistentry>
 378         <term><option>x-systemd.growfs</option></term>
 379
 380         <listitem><para>The file system will be grown to occupy the full block
 381         device. If the file system is already at maximum size, no action will
 382         be performed. It is hence expected that this option remains set even after
 383         the file system has been grown. Only certain file system types are supported,
 384         see
 385         <citerefentry><refentrytitle>systemd-makefs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 386         for details.</para>
 387
 388         <para>Note that this option can only be used in
 389         <filename>/etc/fstab</filename>, and will be ignored when part of the
 390         <varname>Options=</varname> setting in a unit file.</para>
 391
 392         <xi:include href="version-info.xml" xpointer="v236"/></listitem>
 393       </varlistentry>
 394
 395       <varlistentry>
 396         <term><option>x-systemd.pcrfs</option></term>
 397
 398         <listitem><para>Measures file system identity information (mount point, type, label, UUID, partition
 399         label, partition UUID) into PCR 15 after the file system has been mounted. This ensures the
 400         <citerefentry><refentrytitle>systemd-pcrfs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 401         or <filename>systemd-pcrfs-root.service</filename> services are pulled in by the mount unit.</para>
 402
 403         <para>Note that this option can only be used in <filename>/etc/fstab</filename>, and will be ignored
 404         when part of the <varname>Options=</varname> setting in a unit file. It is also implied for the root
 405         and <filename>/usr/</filename> partitions discovered by
 406         <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 407
 408         <xi:include href="version-info.xml" xpointer="v253"/></listitem>
 409       </varlistentry>
 410
 411       <varlistentry>
 412         <term><option>x-systemd.rw-only</option></term>
 413
 414         <listitem><para>If a mount operation fails to mount the file system
 415         read-write, it normally tries mounting the file system read-only instead.
 416         This option disables that behaviour, and causes the mount to fail
 417         immediately instead. This option is translated into the
 418         <varname>ReadWriteOnly=</varname> setting in a unit file.</para>
 419
 420         <xi:include href="version-info.xml" xpointer="v246"/>
 421         </listitem>
 422       </varlistentry>
 423
 424       <varlistentry>
 425         <term><option>_netdev</option></term>
 426
 427         <listitem><para>Normally the file system type is used to determine if a
 428         mount is a "network mount", i.e. if it should only be started after the
 429         network is available. Using this option overrides this detection and
 430         specifies that the mount requires network.</para>
 431
 432         <para>Network mount units are ordered between <filename>remote-fs-pre.target</filename>
 433         and <filename>remote-fs.target</filename>, instead of
 434         <filename>local-fs-pre.target</filename> and <filename>local-fs.target</filename>.
 435         They also pull in <filename>network-online.target</filename> and are ordered after
 436         it and <filename>network.target</filename>.</para>
 437
 438         <xi:include href="version-info.xml" xpointer="v235"/>
 439         </listitem>
 440       </varlistentry>
 441
 442       <varlistentry>
 443         <term><option>noauto</option></term>
 444         <term><option>auto</option></term>
 445
 446         <listitem><para>With <option>noauto</option>, the mount unit will not be added as a dependency for
 447         <filename>local-fs.target</filename> or <filename>remote-fs.target</filename>. This means that it
 448         will not be mounted automatically during boot, unless it is pulled in by some other unit. The
 449         <option>auto</option> option has the opposite meaning and is the default.</para>
 450
 451         <para>Note that if <option>x-systemd.automount</option> (see above) is used, neither
 452         <option>auto</option> nor <option>noauto</option> have any effect. The matching automount unit will
 453         be added as a dependency to the appropriate target.</para>
 454
 455         <xi:include href="version-info.xml" xpointer="v215"/>
 456         </listitem>
 457       </varlistentry>
 458
 459       <varlistentry>
 460         <term><option>nofail</option></term>
 461
 462         <listitem><para>With <option>nofail</option>, this mount will be only wanted, not required, by
 463         <filename>local-fs.target</filename> or <filename>remote-fs.target</filename>. Moreover the mount unit is not
 464         ordered before these target units. This means that the boot will continue without waiting for the mount unit
 465         and regardless whether the mount point can be mounted successfully.</para>
 466
 467         <xi:include href="version-info.xml" xpointer="v215"/>
 468         </listitem>
 469       </varlistentry>
 470
 471       <varlistentry>
 472         <term><option>x-initrd.mount</option></term>
 473
 474         <listitem><para>An additional filesystem to be mounted in the initrd. See
 475         <filename>initrd-fs.target</filename> description in
 476         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>. This
 477         is both an indicator to the initrd to mount this partition early and an indicator to the host to
 478         leave the partition mounted until final shutdown. Or in other words, if this flag is set it is
 479         assumed the mount shall be active during the entire regular runtime of the system, i.e. established
 480         before the initrd transitions into the host all the way until the host transitions to the final
 481         shutdown phase.</para>
 482
 483         <xi:include href="version-info.xml" xpointer="v215"/></listitem>
 484       </varlistentry>
 485     </variablelist>
 486
 487     <para>If a mount point is configured in both
 488     <filename>/etc/fstab</filename> and a unit file that is stored
 489     below <filename>/usr/</filename>, the former will take precedence.
 490     If the unit file is stored below <filename>/etc/</filename>, it
 491     will take precedence. This means: native unit files take
 492     precedence over traditional configuration files, but this is
 493     superseded by the rule that configuration in
 494     <filename>/etc/</filename> will always take precedence over
 495     configuration in <filename>/usr/</filename>.</para>
 496   </refsect1>
 497
 498   <refsect1>
 499     <title>Options</title>
 500
 501     <para>Mount unit files may include [Unit] and [Install] sections, which are described in
 502     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 503     </para>
 504
 505     <para>Mount unit files must include a [Mount] section, which carries
 506     information about the file system mount points it supervises. A
 507     number of options that may be used in this section are shared with
 508     other unit types. These options are documented in
 509     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 510     and
 511     <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 512     The options specific to the [Mount] section of mount units are the
 513     following:</para>
 514
 515     <variablelist class='unit-directives'>
 516
 517       <varlistentry>
 518         <term><varname>What=</varname></term>
 519         <listitem><para>Takes an absolute path of a device node, file or other resource to mount. See
 520         <citerefentry
 521         project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
 522         details. If this refers to a device node, a dependency on the respective device unit is automatically
 523         created. (See
 524         <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 525         for more information.) This option is mandatory. Note that the usual specifier expansion is applied
 526         to this setting, literal percent characters should hence be written as <literal
 527         class='specifiers'>%%</literal>. If this mount is a bind mount and the specified path does not exist
 528         yet it is created as directory.</para></listitem>
 529       </varlistentry>
 530
 531       <varlistentry>
 532         <term><varname>Where=</varname></term>
 533         <listitem><para>Takes an absolute path of a file or directory for the mount point; in particular, the
 534         destination cannot be a symbolic link.  If the mount point does not exist at the time of mounting, it
 535         is created as either a directory or a file. The former is the usual case; the latter is done only if this mount
 536         is a bind mount and the source (<varname>What=</varname>) is not a directory.
 537         This string must be reflected in the unit filename. (See above.) This option
 538         is mandatory.</para></listitem>
 539       </varlistentry>
 540
 541       <varlistentry>
 542         <term><varname>Type=</varname></term>
 543         <listitem><para>Takes a string for the file system type. See
 544         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 545         for details. This setting is optional.</para>
 546
 547         <para>If the type is <literal>overlay</literal>, and <literal>upperdir=</literal> or
 548         <literal>workdir=</literal> are specified as options and they don't exist, they will be created.
 549         </para></listitem>
 550       </varlistentry>
 551
 552       <varlistentry>
 553         <term><varname>Options=</varname></term>
 554
 555         <listitem><para>Mount options to use when mounting. This takes a comma-separated list of options. This setting
 556         is optional. Note that the usual specifier expansion is applied to this setting, literal percent characters
 557         should hence be written as <literal class='specifiers'>%%</literal>.</para></listitem>
 558       </varlistentry>
 559
 560       <varlistentry>
 561         <term><varname>SloppyOptions=</varname></term>
 562
 563         <listitem><para>Takes a boolean argument. If true, parsing of
 564         the options specified in <varname>Options=</varname> is
 565         relaxed, and unknown mount options are tolerated. This
 566         corresponds with
 567         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 568         <parameter>-s</parameter> switch. Defaults to
 569         off.</para>
 570
 571         <xi:include href="version-info.xml" xpointer="v215"/></listitem>
 572       </varlistentry>
 573
 574       <varlistentry>
 575         <term><varname>LazyUnmount=</varname></term>
 576
 577         <listitem><para>Takes a boolean argument. If true, detach the
 578         filesystem from the filesystem hierarchy at time of the unmount
 579         operation, and clean up all references to the filesystem as
 580         soon as they are not busy anymore.
 581         This corresponds with
 582         <citerefentry project='man-pages'><refentrytitle>umount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 583         <parameter>-l</parameter> switch. Defaults to
 584         off.</para>
 585
 586         <xi:include href="version-info.xml" xpointer="v232"/></listitem>
 587       </varlistentry>
 588
 589       <varlistentry>
 590         <term><varname>ReadWriteOnly=</varname></term>
 591
 592         <listitem><para>Takes a boolean argument. If false, a mount
 593         point that shall be mounted read-write but cannot be mounted
 594         so is retried to be mounted read-only. If true the operation
 595         will fail immediately after the read-write mount attempt did
 596         not succeed. This corresponds with
 597         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 598         <parameter>-w</parameter> switch. Defaults to
 599         off.</para>
 600
 601         <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 602       </varlistentry>
 603
 604       <varlistentry>
 605         <term><varname>ForceUnmount=</varname></term>
 606
 607         <listitem><para>Takes a boolean argument. If true, force an
 608         unmount (in case of an unreachable NFS system).
 609         This corresponds with
 610         <citerefentry project='man-pages'><refentrytitle>umount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 611         <parameter>-f</parameter> switch. Defaults to
 612         off.</para>
 613
 614         <xi:include href="version-info.xml" xpointer="v232"/></listitem>
 615       </varlistentry>
 616
 617       <varlistentry>
 618         <term><varname>DirectoryMode=</varname></term>
 619         <listitem><para>Directories of mount points (and any parent
 620         directories) are automatically created if needed. This option
 621         specifies the file system access mode used when creating these
 622         directories. Takes an access mode in octal notation. Defaults
 623         to 0755.</para></listitem>
 624       </varlistentry>
 625
 626       <varlistentry>
 627         <term><varname>TimeoutSec=</varname></term>
 628         <listitem><para>Configures the time to wait for the mount
 629         command to finish. If a command does not exit within the
 630         configured time, the mount will be considered failed and be
 631         shut down again. All commands still running will be terminated
 632         forcibly via <constant>SIGTERM</constant>, and after another
 633         delay of this time with <constant>SIGKILL</constant>. (See
 634         <option>KillMode=</option> in
 635         <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
 636         Takes a unit-less value in seconds, or a time span value such
 637         as "5min 20s". Pass 0 to disable the timeout logic. The
 638         default value is set from <varname>DefaultTimeoutStartSec=</varname> option in
 639         <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 640         </para></listitem>
 641       </varlistentry>
 642     </variablelist>
 643
 644     <xi:include href="systemd.service.xml" xpointer="shared-unit-options" />
 645   </refsect1>
 646
 647   <refsect1>
 648       <title>See Also</title>
 649       <para>
 650         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 651         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 652         <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 653         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 654         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 655         <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 656         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 657         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 658         <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 659         <citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 660         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 661         <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 662         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 663         <citerefentry><refentrytitle>systemd-mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 664       </para>
 665   </refsect1>
 666
 667 </refentry>