"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
+ SPDX-License-Identifier: LGPL-2.1+
+
This file is part of systemd.
Copyright 2010 Lennart Poettering
<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>
- binary is executed in, and in
+ 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. Note that the User= and Group= options are not
- particularly useful for mount units specifying a
- <literal>Type=</literal> option or using configuration not
- specified in <filename>/etc/fstab</filename>;
+ 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>
- will refuse options that are not listed in
- <filename>/etc/fstab</filename> if it is not run as UID 0.</para>
+ 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
noindex='true'>/home/lennart</filename> must be configured in a unit file <filename>home-lennart.mount</filename>.
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="http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
+ url="https://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
File Systems</ulink>.</para>
</refsect1>
<refsect1>
- <title>Automatic Dependencies</title>
-
- <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>
-
- <para>Block device backed file systems automatically gain
- <varname>BindsTo=</varname> and <varname>After=</varname> type
- dependencies on the device unit encapsulating the block
- device (see below).</para>
-
- <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>
-
- <para>For mount units with <varname>DefaultDependencies=yes</varname> in the <literal>[Unit]</literal> section (the
- default) a couple additional dependencies are added. Mount units referring to local file systems automatically gain
- an <varname>After=</varname> dependency on <filename>local-fs-pre.target</filename>. Network mount units
- automatically acquire <varname>After=</varname> dependencies on <filename>remote-fs-pre.target</filename>,
- <filename>network.target</filename> and <filename>network-online.target</filename>. Towards the latter a
- <varname>Wants=</varname> unit is added as well. Mount units referring to local and network file systems are
+ <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>BindsTo=</varname> and <varname>After=</varname> type
+ dependencies on the device unit encapsulating the block
+ device (see below).</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>
+ </refsect1>
+
+ <refsect1>
+ <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>.</para></listitem>
+
+ <listitem><para>Network mount units
+ automatically acquire <varname>After=</varname> dependencies on <filename>remote-fs-pre.target</filename>,
+ <filename>network.target</filename> and <filename>network-online.target</filename>. Towards the latter a
+ <varname>Wants=</varname> unit is added as well.</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. Mount units (regardless if
- local or network) also acquire automatic <varname>Before=</varname> and <varname>Conflicts=</varname> on
- <filename>umount.target</filename> in order to be stopped during shutdown.</para>
-
- <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>
+ string of the unit, which forces systemd to consider the mount unit a network mount.</para>
</refsect1>
<refsect1>
<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
for details about the conversion.</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-timout=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
for details.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>x-systemd.before=</option></term>
+ <term><option>x-systemd.after=</option></term>
+
+ <listitem><para>Configures a <varname>Before=</varname>
+ dependency or <varname>After=</varname> between the created
+ mount unit and 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></listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>x-systemd.requires-mounts-for=</option></term>
for details.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>x-systemd.device-bound</option></term>
+
+ <listitem><para>The block device backed file system will be upgraded
+ to <varname>BindsTo=</varname> dependency. This option is only useful
+ when mounting file systems manually with
+ <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ as the default dependency in this case is <varname>Requires=</varname>.
+ This option is already implied by entries in <filename>/etc/fstab</filename>
+ or by mount units.
+ </para></listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>x-systemd.automount</option></term>
</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>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>x-systemd.makefs</option></term>
+
+ <listitem><para>The file system or swap structure will be intialized
+ 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 initalized.</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>
+ </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></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>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>noauto</option></term>
<term><option>auto</option></term>
- <listitem><para>With <option>noauto</option>, this mount 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>
+ <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. Note that the <option>noauto</option> option has an effect on the
+ mount unit itself only — if <option>x-systemd.automount</option> is used (see above), then the matching
+ automount unit will still be pulled in by these targets.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>What=</varname></term>
- <listitem><para>Takes an absolute path 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.</para></listitem>
+ <listitem><para>Takes an absolute path 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>%%</literal>.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>Where=</varname></term>
- <listitem><para>Takes an absolute path of a directory of the
- mount point. If the mount point does not exist at the time of
+ <listitem><para>Takes an absolute path of a 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. This string must be reflected in the
unit filename. (See above.) This option is
mandatory.</para></listitem>
<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.</para></listitem>
+ <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>%%</literal>.</para></listitem>
</varlistentry>
<varlistentry>
off.</para></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></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></listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>DirectoryMode=</varname></term>
<listitem><para>Directories of mount points (and any parent
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 the manager configuration file's
- <varname>DefaultTimeoutStart=</varname>
+ <varname>DefaultTimeoutStartSec=</varname>
variable.</para></listitem>
</varlistentry>
</variablelist>
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