man/systemd.automount.xml

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   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
  67     <para>Note that automount support on Linux is privileged, automount units are hence only available in the
  68     system service manager (and root's user service manager), but not in unprivileged user's service
  69     manager.</para>
  70   </refsect1>
  71
  72   <refsect1>
  73     <title>Automatic Dependencies</title>
  74
  75     <refsect2>
  76       <title>Implicit Dependencies</title>
  77
  78       <para>The following dependencies are implicitly added:</para>
  79
  80       <itemizedlist>
  81         <listitem><para>If an automount unit is beneath another mount unit in the
  82         file system hierarchy, both a requirement and an ordering
  83         dependency between both units are created automatically.</para></listitem>
  84
  85         <listitem><para>An implicit <varname>Before=</varname> dependency is created
  86         between an automount unit and the mount unit it activates.</para></listitem>
  87       </itemizedlist>
  88     </refsect2>
  89
  90     <refsect2>
  91       <title>Default Dependencies</title>
  92
  93       <para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para>
  94
  95       <itemizedlist>
  96         <listitem><para>Automount units acquire automatic <varname>Before=</varname> and
  97         <varname>Conflicts=</varname> on <filename>umount.target</filename> in order to be stopped during
  98         shutdown.</para></listitem>
  99
 100         <listitem><para>Automount units automatically gain an <varname>After=</varname> dependency
 101         on <filename>local-fs-pre.target</filename>, and a <varname>Before=</varname> dependency on
 102         <filename>local-fs.target</filename>.</para></listitem>
 103       </itemizedlist>
 104     </refsect2>
 105   </refsect1>
 106
 107   <refsect1>
 108     <title><filename>fstab</filename></title>
 109
 110     <para>Automount units may either be configured via unit files, or
 111     via <filename>/etc/fstab</filename> (see
 112     <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 113     for details).</para>
 114
 115     <para>For details how systemd parses
 116     <filename>/etc/fstab</filename> see
 117     <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 118
 119     <para>If an automount point is configured in both
 120     <filename>/etc/fstab</filename> and a unit file, the configuration
 121     in the latter takes precedence.</para>
 122   </refsect1>
 123
 124   <refsect1>
 125     <title>Options</title>
 126
 127     <para>Automount files must include an [Automount] section, which
 128     carries information about the file system automount points it
 129     supervises. The options specific to the [Automount] section of
 130     automount units are the following:</para>
 131
 132     <variablelist class='unit-directives'>
 133
 134       <varlistentry>
 135         <term><varname>Where=</varname></term>
 136         <listitem><para>Takes an absolute path of a directory of the
 137         automount point. If the automount point does not exist at time
 138         that the automount point is installed, it is created. This
 139         string must be reflected in the unit filename. (See above.)
 140         This option is mandatory.</para></listitem>
 141       </varlistentry>
 142
 143       <varlistentry>
 144         <term><varname>DirectoryMode=</varname></term>
 145         <listitem><para>Directories of automount points (and any
 146         parent directories) are automatically created if needed. This
 147         option specifies the file system access mode used when
 148         creating these directories. Takes an access mode in octal
 149         notation. Defaults to 0755.</para></listitem>
 150       </varlistentry>
 151       <varlistentry>
 152         <term><varname>TimeoutIdleSec=</varname></term>
 153         <listitem><para>Configures an idle timeout. Once the mount has been
 154         idle for the specified time, systemd will attempt to unmount. Takes a
 155         unit-less value in seconds, or a time span value such as "5min 20s".
 156         Pass 0 to disable the timeout logic. The timeout is disabled by
 157         default.</para></listitem>
 158       </varlistentry>
 159     </variablelist>
 160   </refsect1>
 161
 162   <refsect1>
 163       <title>See Also</title>
 164       <para>
 165         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 166         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 167         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 168         <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 169         <citerefentry project='man-pages'><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 170         <citerefentry project='die-net'><refentrytitle>automount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 171         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 172       </para>
 173   </refsect1>
 174
 175 </refentry>