man/systemd.automount.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="systemd.automount">
   7   <refentryinfo>
   8     <title>systemd.automount</title>
   9     <productname>systemd</productname>
  10   </refentryinfo>
  11
  12   <refmeta>
  13     <refentrytitle>systemd.automount</refentrytitle>
  14     <manvolnum>5</manvolnum>
  15   </refmeta>
  16
  17   <refnamediv>
  18     <refname>systemd.automount</refname>
  19     <refpurpose>Automount unit configuration</refpurpose>
  20   </refnamediv>
  21
  22   <refsynopsisdiv>
  23     <para><filename><replaceable>automount</replaceable>.automount</filename></para>
  24   </refsynopsisdiv>
  25
  26   <refsect1>
  27     <title>Description</title>
  28
  29     <para>A unit configuration file whose name ends in
  30     <literal>.automount</literal> encodes information about a file
  31     system automount point controlled and supervised by
  32     systemd.</para>
  33
  34     <para>This man page lists the configuration options specific to
  35     this unit type. See
  36     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  37     for the common options of all unit configuration files. The common
  38     configuration items are configured in the generic [Unit] and
  39     [Install] sections. The automount specific configuration options
  40     are configured in the [Automount] section.</para>
  41
  42     <para>Automount units must be named after the automount directories they control. Example: the automount point
  43     <filename index="false">/home/lennart</filename> must be configured in a unit file
  44     <filename>home-lennart.automount</filename>. For details about the escaping logic used to convert a file system
  45     path to a unit name see
  46     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. Note that
  47     automount units cannot be templated, nor is it possible to add multiple names to an automount unit by creating
  48     additional symlinks to its unit file.</para>
  49
  50     <para>For each automount unit file a matching mount unit file (see
  51     <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  52     for details) must exist which is activated when the automount path
  53     is accessed. Example: if an automount unit
  54     <filename>home-lennart.automount</filename> is active and the user
  55     accesses <filename>/home/lennart</filename> the mount unit
  56     <filename>home-lennart.mount</filename> will be activated.</para>
  57
  58     <para>Automount units may be used to implement on-demand mounting
  59     as well as parallelized mounting of file systems.</para>
  60
  61     <para>Note that automount units are separate from the mount itself, so you
  62     should not set <varname>After=</varname> or <varname>Requires=</varname>
  63     for mount dependencies here. For example, you should not set
  64     <varname>After=network-online.target</varname> or similar on network
  65     filesystems. Doing so may result in an ordering cycle.</para>
  66   </refsect1>
  67
  68   <refsect1>
  69     <title>Automatic Dependencies</title>
  70
  71     <refsect2>
  72       <title>Implicit Dependencies</title>
  73
  74       <para>The following dependencies are implicitly added:</para>
  75
  76       <itemizedlist>
  77         <listitem><para>If an automount unit is beneath another mount unit in the
  78         file system hierarchy, both a requirement and an ordering
  79         dependency between both units are created automatically.</para></listitem>
  80
  81         <listitem><para>An implicit <varname>Before=</varname> dependency is created
  82         between an automount unit and the mount unit it activates.</para></listitem>
  83       </itemizedlist>
  84     </refsect2>
  85
  86     <refsect2>
  87       <title>Default Dependencies</title>
  88
  89       <para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
  90
  91       <itemizedlist>
  92         <listitem><para>Automount units acquire automatic <varname>Before=</varname> and
  93         <varname>Conflicts=</varname> on <filename>umount.target</filename> in order to be stopped during
  94         shutdown.</para></listitem>
  95
  96         <listitem><para>Automount units automatically gain an <varname>After=</varname> dependency
  97         on <filename>local-fs-pre.target</filename>, and a <varname>Before=</varname> dependency on
  98         <filename>local-fs.target</filename>.</para></listitem>
  99       </itemizedlist>
 100     </refsect2>
 101   </refsect1>
 102
 103   <refsect1>
 104     <title><filename>fstab</filename></title>
 105
 106     <para>Automount units may either be configured via unit files, or
 107     via <filename>/etc/fstab</filename> (see
 108     <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 109     for details).</para>
 110
 111     <para>For details how systemd parses
 112     <filename>/etc/fstab</filename> see
 113     <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 114
 115     <para>If an automount point is configured in both
 116     <filename>/etc/fstab</filename> and a unit file, the configuration
 117     in the latter takes precedence.</para>
 118   </refsect1>
 119
 120   <refsect1>
 121     <title>Options</title>
 122
 123     <para>Automount files must include an [Automount] section, which
 124     carries information about the file system automount points it
 125     supervises. The options specific to the [Automount] section of
 126     automount units are the following:</para>
 127
 128     <variablelist class='unit-directives'>
 129
 130       <varlistentry>
 131         <term><varname>Where=</varname></term>
 132         <listitem><para>Takes an absolute path of a directory of the
 133         automount point. If the automount point does not exist at time
 134         that the automount point is installed, it is created. This
 135         string must be reflected in the unit filename. (See above.)
 136         This option is mandatory.</para></listitem>
 137       </varlistentry>
 138
 139       <varlistentry>
 140         <term><varname>DirectoryMode=</varname></term>
 141         <listitem><para>Directories of automount points (and any
 142         parent directories) are automatically created if needed. This
 143         option specifies the file system access mode used when
 144         creating these directories. Takes an access mode in octal
 145         notation. Defaults to 0755.</para></listitem>
 146       </varlistentry>
 147       <varlistentry>
 148         <term><varname>TimeoutIdleSec=</varname></term>
 149         <listitem><para>Configures an idle timeout. Once the mount has been
 150         idle for the specified time, systemd will attempt to unmount. Takes a
 151         unit-less value in seconds, or a time span value such as "5min 20s".
 152         Pass 0 to disable the timeout logic. The timeout is disabled by
 153         default.</para></listitem>
 154       </varlistentry>
 155     </variablelist>
 156   </refsect1>
 157
 158   <refsect1>
 159       <title>See Also</title>
 160       <para>
 161         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 162         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 163         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 164         <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 165         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 166         <citerefentry project='die-net'><refentrytitle>automount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 167         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 168       </para>
 169   </refsect1>
 170
 171 </refentry>