man/systemd.mount.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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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.
 140         </para></listitem>
 141
 142         <listitem><para>Network mount units automatically acquire <varname>After=</varname> dependencies on
 143         <filename>remote-fs-pre.target</filename>, <filename>network.target</filename>,
 144         plus <varname>After=</varname> and <varname>Wants=</varname> dependencies on <filename>network-online.target</filename>,
 145         and a <varname>Before=</varname> dependency on <filename>remote-fs.target</filename>, unless
 146         one or more mount options among <option>nofail</option>, <option>x-systemd.wanted-by=</option>,
 147         and <option>x-systemd.required-by=</option> is set.</para></listitem>
 148       </itemizedlist>
 149
 150       <para>Mount units referring to local and network file systems are distinguished by their file system type
 151       specification. In some cases this is not sufficient (for example network block device based mounts, such as
 152       iSCSI), in which case <option>_netdev</option> may be added to the mount option string of the unit, which forces
 153       systemd to consider the mount unit a network mount.</para>
 154     </refsect2>
 155   </refsect1>
 156
 157   <refsect1>
 158     <title><filename>fstab</filename></title>
 159
 160     <para>Mount units may either be configured via unit files, or via <filename>/etc/fstab</filename> (see
 161     <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 162     for details). Mounts listed in <filename>/etc/fstab</filename> will be converted into native units
 163     dynamically at boot and when the configuration of the system manager is reloaded. In general, configuring
 164     mount points through <filename>/etc/fstab</filename> is the preferred approach to manage mounts for
 165     humans. For tooling, writing mount units should be preferred over editing <filename>/etc/fstab</filename>.
 166     See <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 167     for details about the conversion from <filename>/etc/fstab</filename> to mount units.</para>
 168
 169     <para>The NFS mount option <option>bg</option> for NFS background mounts
 170     as documented in <citerefentry project='man-pages'><refentrytitle>nfs</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 171     is detected by <command>systemd-fstab-generator</command> and the options
 172     are transformed so that systemd fulfills the job-control implications of
 173     that option.  Specifically <command>systemd-fstab-generator</command> acts
 174     as though <literal>x-systemd.mount-timeout=infinity,retry=10000</literal> was
 175     prepended to the option list, and <literal>fg,nofail</literal> was appended.
 176     Depending on specific requirements, it may be appropriate to provide some of
 177     these options explicitly, or to make use of the
 178     <literal>x-systemd.automount</literal> option described below instead
 179     of using <literal>bg</literal>.</para>
 180
 181     <para>When reading <filename>/etc/fstab</filename> a few special
 182     mount options are understood by systemd which influence how
 183     dependencies are created for mount points. systemd will create a
 184     dependency of type <varname>Wants=</varname> or
 185     <option>Requires=</option> (see option <option>nofail</option>
 186     below), from either <filename>local-fs.target</filename> or
 187     <filename>remote-fs.target</filename>, depending whether the file
 188     system is local or remote.</para>
 189
 190     <variablelist class='fstab-options'>
 191
 192       <varlistentry>
 193         <term><option>x-systemd.requires=</option></term>
 194
 195         <listitem><para>Configures a <varname>Requires=</varname> and
 196         an <varname>After=</varname> dependency between the created
 197         mount unit and another systemd unit, such as a device or mount
 198         unit. The argument should be a unit name, or an absolute path
 199         to a device node or mount point.  This option may be specified
 200         more than once. This option is particularly useful for mount
 201         point declarations that need an additional device to be around
 202         (such as an external journal device for journal file systems)
 203         or an additional mount to be in place (such as an overlay file
 204         system that merges multiple mount points). See
 205         <varname>After=</varname> and <varname>Requires=</varname> in
 206         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 207         for details.</para>
 208
 209         <para>Note that this option always applies to the created mount unit
 210         only regardless whether <option>x-systemd.automount</option> has been
 211         specified.</para>
 212
 213         <xi:include href="version-info.xml" xpointer="v220"/></listitem>
 214       </varlistentry>
 215
 216       <varlistentry>
 217         <term><option>x-systemd.before=</option></term>
 218         <term><option>x-systemd.after=</option></term>
 219
 220         <listitem><para>In the created mount unit, configures a
 221         <varname>Before=</varname> or <varname>After=</varname>
 222         dependency on another systemd unit, such as a mount unit.
 223         The argument should be a unit name or an absolute path
 224         to a mount point. This option may be specified more than once.
 225         This option is particularly useful for mount point declarations
 226         with <option>nofail</option> option that are mounted
 227         asynchronously but need to be mounted before or after some unit
 228         start, for example, before <filename>local-fs.target</filename>
 229         unit.
 230         See <varname>Before=</varname> and <varname>After=</varname> in
 231         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 232         for details.</para>
 233
 234         <para>Note that these options always apply to the created mount unit
 235         only regardless whether <option>x-systemd.automount</option> has been
 236         specified.</para>
 237
 238         <xi:include href="version-info.xml" xpointer="v233"/></listitem>
 239       </varlistentry>
 240
 241       <varlistentry>
 242         <term><option>x-systemd.wanted-by=</option></term>
 243         <term><option>x-systemd.required-by=</option></term>
 244
 245         <listitem><para>In the created mount unit, configures a <varname>WantedBy=</varname> or
 246         <varname>RequiredBy=</varname> dependency on another unit. This option may be specified more than once.
 247         If this is specified, the default dependencies (see above) other than <filename>umount.target</filename>
 248         on the created mount unit, e.g. <filename>local-fs.target</filename>, are not automatically created.
 249         Hence it is likely that some ordering dependencies need to be set up manually through
 250         <option>x-systemd.before=</option> and <option>x-systemd.after=</option>. See <varname>WantedBy=</varname>
 251         and <varname>RequiredBy=</varname> in
 252         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 253         for details.</para>
 254
 255         <xi:include href="version-info.xml" xpointer="v245"/></listitem>
 256       </varlistentry>
 257
 258       <varlistentry>
 259         <term><option>x-systemd.wants-mounts-for=</option></term>
 260         <term><option>x-systemd.requires-mounts-for=</option></term>
 261
 262         <listitem><para>Configures a
 263         <varname>RequiresMountsFor=</varname> or <varname>WantsMountsFor=</varname>
 264         dependency between the created mount unit and other mount units. The
 265         argument must be an absolute path. This option may be specified more than
 266         once. See <varname>RequiresMountsFor=</varname> or <varname>WantsMountsFor=</varname> in
 267         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 268         for details.</para>
 269
 270         <xi:include href="version-info.xml" xpointer="v220"/></listitem>
 271        </varlistentry>
 272
 273       <varlistentry>
 274         <term><option>x-systemd.device-bound=</option></term>
 275
 276         <listitem><para>Takes a boolean argument. If true or no argument, a <varname>BindsTo=</varname> dependency
 277         on the backing device is set. If false, the mount unit is not stopped no matter whether the backing device
 278         is still present. This is useful when the file system is backed by volume managers. If not set, and the mount
 279         comes from unit fragments, i.e. generated from <filename>/etc/fstab</filename> by <citerefentry>
 280         <refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> or loaded from
 281         a manually configured mount unit, a combination of <varname>Requires=</varname> and <varname>StopPropagatedFrom=</varname>
 282         dependencies is set on the backing device. If doesn't, only <varname>Requires=</varname> is used.</para>
 283
 284         <xi:include href="version-info.xml" xpointer="v233"/></listitem>
 285       </varlistentry>
 286
 287       <varlistentry>
 288         <term><option>x-systemd.automount</option></term>
 289
 290         <listitem><para>An automount unit will be created for the file
 291         system. See
 292         <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 293         for details.</para>
 294
 295         <xi:include href="version-info.xml" xpointer="v215"/></listitem>
 296       </varlistentry>
 297
 298       <varlistentry>
 299         <term><option>x-systemd.idle-timeout=</option></term>
 300
 301         <listitem><para>Configures the idle timeout of the
 302         automount unit. See <varname>TimeoutIdleSec=</varname> in
 303         <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 304         for details.</para>
 305
 306         <xi:include href="version-info.xml" xpointer="v220"/></listitem>
 307       </varlistentry>
 308
 309       <varlistentry id='device-timeout'>
 310         <term><option>x-systemd.device-timeout=</option></term>
 311
 312         <listitem><para>Configure how long systemd should wait for a
 313         device to show up before giving up on an entry from
 314         <filename>/etc/fstab</filename>. Specify a time in seconds or
 315         explicitly append a unit such as <literal>s</literal>,
 316         <literal>min</literal>, <literal>h</literal>,
 317         <literal>ms</literal>.</para>
 318
 319         <para>Note that this option can only be used in
 320         <filename>/etc/fstab</filename>, and will be
 321         ignored when part of the <varname>Options=</varname>
 322         setting in a unit file.</para>
 323
 324         <xi:include href="version-info.xml" xpointer="v215"/>
 325         </listitem>
 326       </varlistentry>
 327
 328       <varlistentry>
 329         <term><option>x-systemd.mount-timeout=</option></term>
 330
 331         <listitem><para>Configure how long systemd should wait for the
 332         mount command to finish before giving up on an entry from
 333         <filename>/etc/fstab</filename>. Specify a time in seconds or
 334         explicitly append a unit such as <literal>s</literal>,
 335         <literal>min</literal>, <literal>h</literal>,
 336         <literal>ms</literal>.</para>
 337
 338         <para>Note that this option can only be used in
 339         <filename>/etc/fstab</filename>, and will be
 340         ignored when part of the <varname>Options=</varname>
 341         setting in a unit file.</para>
 342
 343         <para>See <varname>TimeoutSec=</varname> below for
 344         details.</para>
 345
 346         <xi:include href="version-info.xml" xpointer="v233"/>
 347         </listitem>
 348       </varlistentry>
 349
 350       <varlistentry>
 351         <term><option>x-systemd.makefs</option></term>
 352
 353         <listitem><para>The file system will be initialized
 354         on the device. If the device is not "empty", i.e. it contains any signature,
 355         the operation will be skipped. It is hence expected that this option
 356         remains set even after the device has been initialized.</para>
 357
 358         <para>Note that this option can only be used in
 359         <filename>/etc/fstab</filename>, and will be ignored when part of the
 360         <varname>Options=</varname> setting in a unit file.</para>
 361
 362         <para>See
 363         <citerefentry><refentrytitle>systemd-makefs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 364         </para>
 365
 366         <para><citerefentry project='man-pages'><refentrytitle>wipefs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 367         may be used to remove any signatures from a block device to force
 368         <option>x-systemd.makefs</option> to reinitialize the device.</para>
 369
 370         <xi:include href="version-info.xml" xpointer="v236"/>
 371         </listitem>
 372       </varlistentry>
 373
 374       <varlistentry>
 375         <term><option>x-systemd.growfs</option></term>
 376
 377         <listitem><para>The file system will be grown to occupy the full block
 378         device. If the file system is already at maximum size, no action will
 379         be performed. It is hence expected that this option remains set even after
 380         the file system has been grown. Only certain file system types are supported,
 381         see
 382         <citerefentry><refentrytitle>systemd-makefs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 383         for details.</para>
 384
 385         <para>Note that this option can only be used in
 386         <filename>/etc/fstab</filename>, and will be ignored when part of the
 387         <varname>Options=</varname> setting in a unit file.</para>
 388
 389         <xi:include href="version-info.xml" xpointer="v236"/></listitem>
 390       </varlistentry>
 391
 392       <varlistentry>
 393         <term><option>x-systemd.pcrfs</option></term>
 394
 395         <listitem><para>Measures file system identity information (mount point, type, label, UUID, partition
 396         label, partition UUID) into PCR 15 after the file system has been mounted. This ensures the
 397         <citerefentry><refentrytitle>systemd-pcrfs@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 398         or <filename>systemd-pcrfs-root.service</filename> services are pulled in by the mount unit.</para>
 399
 400         <para>Note that this option can only be used in <filename>/etc/fstab</filename>, and will be ignored
 401         when part of the <varname>Options=</varname> setting in a unit file. It is also implied for the root
 402         and <filename>/usr/</filename> partitions discovered by
 403         <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 404
 405         <xi:include href="version-info.xml" xpointer="v253"/></listitem>
 406       </varlistentry>
 407
 408       <varlistentry>
 409         <term><option>x-systemd.rw-only</option></term>
 410
 411         <listitem><para>If a mount operation fails to mount the file system
 412         read-write, it normally tries mounting the file system read-only instead.
 413         This option disables that behaviour, and causes the mount to fail
 414         immediately instead. This option is translated into the
 415         <varname>ReadWriteOnly=</varname> setting in a unit file.</para>
 416
 417         <xi:include href="version-info.xml" xpointer="v246"/>
 418         </listitem>
 419       </varlistentry>
 420
 421       <varlistentry>
 422         <term><option>_netdev</option></term>
 423
 424         <listitem><para>Normally the file system type is used to determine if a
 425         mount is a "network mount", i.e. if it should only be started after the
 426         network is available. Using this option overrides this detection and
 427         specifies that the mount requires network.</para>
 428
 429         <para>Network mount units are ordered between <filename>remote-fs-pre.target</filename>
 430         and <filename>remote-fs.target</filename>, instead of
 431         <filename>local-fs-pre.target</filename> and <filename>local-fs.target</filename>.
 432         They also pull in <filename>network-online.target</filename> and are ordered after
 433         it and <filename>network.target</filename>.</para>
 434
 435         <xi:include href="version-info.xml" xpointer="v235"/>
 436         </listitem>
 437       </varlistentry>
 438
 439       <varlistentry>
 440         <term><option>noauto</option></term>
 441         <term><option>auto</option></term>
 442
 443         <listitem><para>With <option>noauto</option>, the mount unit will not be added as a dependency for
 444         <filename>local-fs.target</filename> or <filename>remote-fs.target</filename>. This means that it
 445         will not be mounted automatically during boot, unless it is pulled in by some other unit. The
 446         <option>auto</option> option has the opposite meaning and is the default.</para>
 447
 448         <para>Note that if <option>x-systemd.automount</option> (see above) is used, neither
 449         <option>auto</option> nor <option>noauto</option> have any effect. The matching automount unit will
 450         be added as a dependency to the appropriate target.</para>
 451
 452         <xi:include href="version-info.xml" xpointer="v215"/>
 453         </listitem>
 454       </varlistentry>
 455
 456       <varlistentry>
 457         <term><option>nofail</option></term>
 458
 459         <listitem><para>With <option>nofail</option>, this mount will be only wanted, not required, by
 460         <filename>local-fs.target</filename> or <filename>remote-fs.target</filename>. Moreover the mount unit is not
 461         ordered before these target units. This means that the boot will continue without waiting for the mount unit
 462         and regardless whether the mount point can be mounted successfully.</para>
 463
 464         <xi:include href="version-info.xml" xpointer="v215"/>
 465         </listitem>
 466       </varlistentry>
 467
 468       <varlistentry>
 469         <term><option>x-initrd.mount</option></term>
 470
 471         <listitem><para>An additional filesystem to be mounted in the initrd. See
 472         <filename>initrd-fs.target</filename> description in
 473         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>. This
 474         is both an indicator to the initrd to mount this partition early and an indicator to the host to
 475         leave the partition mounted until final shutdown. Or in other words, if this flag is set it is
 476         assumed the mount shall be active during the entire regular runtime of the system, i.e. established
 477         before the initrd transitions into the host all the way until the host transitions to the final
 478         shutdown phase.</para>
 479
 480         <xi:include href="version-info.xml" xpointer="v215"/></listitem>
 481       </varlistentry>
 482     </variablelist>
 483
 484     <para>If a mount point is configured in both
 485     <filename>/etc/fstab</filename> and a unit file that is stored
 486     below <filename>/usr/</filename>, the former will take precedence.
 487     If the unit file is stored below <filename>/etc/</filename>, it
 488     will take precedence. This means: native unit files take
 489     precedence over traditional configuration files, but this is
 490     superseded by the rule that configuration in
 491     <filename>/etc/</filename> will always take precedence over
 492     configuration in <filename>/usr/</filename>.</para>
 493   </refsect1>
 494
 495   <refsect1>
 496     <title>Options</title>
 497
 498     <para>Mount unit files may include [Unit] and [Install] sections, which are described in
 499     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 500     </para>
 501
 502     <para>Mount unit files must include a [Mount] section, which carries
 503     information about the file system mount points it supervises. A
 504     number of options that may be used in this section are shared with
 505     other unit types. These options are documented in
 506     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 507     and
 508     <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 509     The options specific to the [Mount] section of mount units are the
 510     following:</para>
 511
 512     <variablelist class='unit-directives'>
 513
 514       <varlistentry>
 515         <term><varname>What=</varname></term>
 516         <listitem><para>Takes an absolute path of a device node, file or other resource to mount. See
 517         <citerefentry
 518         project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry> for
 519         details. If this refers to a device node, a dependency on the respective device unit is automatically
 520         created. (See
 521         <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 522         for more information.) This option is mandatory. Note that the usual specifier expansion is applied
 523         to this setting, literal percent characters should hence be written as <literal
 524         class='specifiers'>%%</literal>. If this mount is a bind mount and the specified path does not exist
 525         yet it is created as directory.</para></listitem>
 526       </varlistentry>
 527
 528       <varlistentry>
 529         <term><varname>Where=</varname></term>
 530         <listitem><para>Takes an absolute path of a file or directory for the mount point; in particular, the
 531         destination cannot be a symbolic link.  If the mount point does not exist at the time of mounting, it
 532         is created as either a directory or a file. The former is the usual case; the latter is done only if this mount
 533         is a bind mount and the source (<varname>What=</varname>) is not a directory.
 534         This string must be reflected in the unit filename. (See above.) This option
 535         is mandatory.</para></listitem>
 536       </varlistentry>
 537
 538       <varlistentry>
 539         <term><varname>Type=</varname></term>
 540         <listitem><para>Takes a string for the file system type. See
 541         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 542         for details. This setting is optional.</para>
 543
 544         <para>If the type is <literal>overlay</literal>, and <literal>upperdir=</literal> or
 545         <literal>workdir=</literal> are specified as options and they don't exist, they will be created.
 546         </para></listitem>
 547       </varlistentry>
 548
 549       <varlistentry>
 550         <term><varname>Options=</varname></term>
 551
 552         <listitem><para>Mount options to use when mounting. This takes a comma-separated list of options. This setting
 553         is optional. Note that the usual specifier expansion is applied to this setting, literal percent characters
 554         should hence be written as <literal class='specifiers'>%%</literal>.</para></listitem>
 555       </varlistentry>
 556
 557       <varlistentry>
 558         <term><varname>SloppyOptions=</varname></term>
 559
 560         <listitem><para>Takes a boolean argument. If true, parsing of
 561         the options specified in <varname>Options=</varname> is
 562         relaxed, and unknown mount options are tolerated. This
 563         corresponds with
 564         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 565         <parameter>-s</parameter> switch. Defaults to
 566         off.</para>
 567
 568         <xi:include href="version-info.xml" xpointer="v215"/></listitem>
 569       </varlistentry>
 570
 571       <varlistentry>
 572         <term><varname>LazyUnmount=</varname></term>
 573
 574         <listitem><para>Takes a boolean argument. If true, detach the
 575         filesystem from the filesystem hierarchy at time of the unmount
 576         operation, and clean up all references to the filesystem as
 577         soon as they are not busy anymore.
 578         This corresponds with
 579         <citerefentry project='man-pages'><refentrytitle>umount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 580         <parameter>-l</parameter> switch. Defaults to
 581         off.</para>
 582
 583         <xi:include href="version-info.xml" xpointer="v232"/></listitem>
 584       </varlistentry>
 585
 586       <varlistentry>
 587         <term><varname>ReadWriteOnly=</varname></term>
 588
 589         <listitem><para>Takes a boolean argument. If false, a mount
 590         point that shall be mounted read-write but cannot be mounted
 591         so is retried to be mounted read-only. If true the operation
 592         will fail immediately after the read-write mount attempt did
 593         not succeed. This corresponds with
 594         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 595         <parameter>-w</parameter> switch. Defaults to
 596         off.</para>
 597
 598         <xi:include href="version-info.xml" xpointer="v246"/></listitem>
 599       </varlistentry>
 600
 601       <varlistentry>
 602         <term><varname>ForceUnmount=</varname></term>
 603
 604         <listitem><para>Takes a boolean argument. If true, force an
 605         unmount (in case of an unreachable NFS system).
 606         This corresponds with
 607         <citerefentry project='man-pages'><refentrytitle>umount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
 608         <parameter>-f</parameter> switch. Defaults to
 609         off.</para>
 610
 611         <xi:include href="version-info.xml" xpointer="v232"/></listitem>
 612       </varlistentry>
 613
 614       <varlistentry>
 615         <term><varname>DirectoryMode=</varname></term>
 616         <listitem><para>Directories of mount points (and any parent
 617         directories) are automatically created if needed. This option
 618         specifies the file system access mode used when creating these
 619         directories. Takes an access mode in octal notation. Defaults
 620         to 0755.</para></listitem>
 621       </varlistentry>
 622
 623       <varlistentry>
 624         <term><varname>TimeoutSec=</varname></term>
 625         <listitem><para>Configures the time to wait for the mount
 626         command to finish. If a command does not exit within the
 627         configured time, the mount will be considered failed and be
 628         shut down again. All commands still running will be terminated
 629         forcibly via <constant>SIGTERM</constant>, and after another
 630         delay of this time with <constant>SIGKILL</constant>. (See
 631         <option>KillMode=</option> in
 632         <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
 633         Takes a unit-less value in seconds, or a time span value such
 634         as "5min 20s". Pass 0 to disable the timeout logic. The
 635         default value is set from <varname>DefaultTimeoutStartSec=</varname> option in
 636         <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 637         </para></listitem>
 638       </varlistentry>
 639     </variablelist>
 640
 641     <xi:include href="systemd.service.xml" xpointer="shared-unit-options" />
 642   </refsect1>
 643
 644   <refsect1>
 645       <title>See Also</title>
 646       <para>
 647         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 648         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 649         <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 650         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 651         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 652         <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 653         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 654         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 655         <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 656         <citerefentry project='man-pages'><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 657         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 658         <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 659         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 660         <citerefentry><refentrytitle>systemd-mount</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 661       </para>
 662   </refsect1>
 663
 664 </refentry>