man/systemd.mount.xml

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   9   Copyright 2010 Lennart Poettering
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  24
  25 <refentry id="systemd.mount">
  26         <refentryinfo>
  27                 <title>systemd.mount</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemd.mount</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.mount</refname>
  47                 <refpurpose>Mount unit configuration</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.mount</filename></para>
  52         </refsynopsisdiv>
  53
  54         <refsect1>
  55                 <title>Description</title>
  56
  57                 <para>A unit configuration file whose name ends in
  58                 <filename>.mount</filename> encodes information about
  59                 a file system mount point controlled and supervised by
  60                 systemd.</para>
  61
  62                 <para>This man page lists the configuration options
  63                 specific to this unit type. See
  64                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  65                 for the common options of all unit configuration
  66                 files. The common configuration items are configured
  67                 in the generic [Unit] and [Install] sections. The
  68                 mount specific configuration options are configured
  69                 in the [Mount] section.</para>
  70
  71                 <para>Additional options are listed in
  72                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
  73                 which define the execution environment the
  74                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  75                 binary is executed in, and in
  76                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  77                 which define the way the processes are
  78                 terminated. The User= and Group= options are not useful
  79                 for mount units specifying a Type= option; the mount
  80                 binary must run as root if there is a specified type.</para>
  81
  82                 <para>Mount units must be named after the mount point
  83                 directories they control. Example: the mount point
  84                 <filename>/home/lennart</filename> must be configured
  85                 in a unit file
  86                 <filename>home-lennart.mount</filename>. For details
  87                 about the escaping logic used to convert a file system
  88                 path to a unit name see
  89                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
  90
  91                 <para>Optionally, a mount unit may be accompanied by
  92                 an automount unit, to allow on-demand or parallelized
  93                 mounting. See
  94                 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
  95
  96                 <para>If a mount point is beneath another mount point
  97                 in the file system hierarchy, a dependency between both
  98                 units is created automatically.</para>
  99
 100                 <para>Mount points created at runtime independent on
 101                 unit files or <filename>/etc/fstab</filename> will be
 102                 monitored by systemd and appear like any other mount
 103                 unit in systemd.</para>
 104         </refsect1>
 105
 106         <refsect1>
 107                 <title><filename>/etc/fstab</filename></title>
 108
 109                 <para>Mount units may either be configured via unit
 110                 files, or via <filename>/etc/fstab</filename> (see
 111                 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 112                 for details). Mounts listed in
 113                 <filename>/etc/fstab</filename> will be converted into
 114                 native units dynamically at boot and when the
 115                 configuration of the system manager is reloaded. See
 116                 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 117                 for details about the conversion.</para>
 118
 119                 <para>When reading <filename>/etc/fstab</filename> a
 120                 few special mount options are understood by systemd
 121                 which influence how dependencies are created for mount
 122                 points from <filename>/etc/fstab</filename>. systemd
 123                 will create a dependency of type
 124                 <option>Wants</option> from either
 125                 <filename>local-fs.target</filename> or
 126                 <filename>remote-fs.target</filename>, depending
 127                 whether the file system is local or remote. If
 128                 <option>x-systemd.automount</option> is set, an
 129                 automount unit will be created for the file
 130                 system. See
 131                 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 132                 for details. If
 133                 <option>x-systemd.device-timeout=</option> is
 134                 specified it may be used to configure how long systemd
 135                 should wait for a device to show up before giving up
 136                 on an entry from
 137                 <filename>/etc/fstab</filename>. Specify a time in
 138                 seconds or explicitly specify a unit as
 139                 <literal>s</literal>, <literal>min</literal>,
 140                 <literal>h</literal>, <literal>ms</literal>.</para>
 141
 142                 <para>If a mount point is configured in both
 143                 <filename>/etc/fstab</filename> and a unit file, the
 144                 configuration in the latter takes precedence.</para>
 145         </refsect1>
 146
 147         <refsect1>
 148                 <title>Options</title>
 149
 150                 <para>Mount files must include a [Mount] section,
 151                 which carries information about the file system mount points it
 152                 supervises. A number of options that may be used in
 153                 this section are shared with other unit types. These
 154                 options are documented in
 155                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 156                 and
 157                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
 158                 options specific to the [Mount] section of mount
 159                 units are the following:</para>
 160
 161                 <variablelist>
 162
 163                         <varlistentry>
 164                                 <term><varname>What=</varname></term>
 165                                 <listitem><para>Takes an absolute path
 166                                 of a device node, file or other
 167                                 resource to mount. See
 168                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 169                                 for details. If this refers to a
 170                                 device node, a dependency on the
 171                                 respective device unit is
 172                                 automatically created. (See
 173                                 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.)
 174                                 This option is
 175                                 mandatory.</para></listitem>
 176                         </varlistentry>
 177
 178                         <varlistentry>
 179                                 <term><varname>Where=</varname></term>
 180                                 <listitem><para>Takes an absolute path
 181                                 of a directory of the mount point. If
 182                                 the mount point does not exist at the
 183                                 time of mounting, it is created. This
 184                                 string must be reflected in the unit
 185                                 file name. (See above.) This option is
 186                                 mandatory.</para></listitem>
 187                         </varlistentry>
 188
 189                         <varlistentry>
 190                                 <term><varname>Type=</varname></term>
 191                                 <listitem><para>Takes a string for the
 192                                 filesystem type. See
 193                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 194                                 for details. This setting is
 195                                 optional.</para></listitem>
 196                         </varlistentry>
 197
 198                         <varlistentry>
 199                                 <term><varname>Options=</varname></term>
 200
 201                                 <listitem><para>Mount options to use
 202                                 when mounting. This takes a comma
 203                                 separated list of options. This
 204                                 setting is optional.</para></listitem>
 205                         </varlistentry>
 206
 207                         <varlistentry>
 208                                 <term><varname>DirectoryMode=</varname></term>
 209                                 <listitem><para>Directories of mount
 210                                 points (and any parent directories)
 211                                 are automatically created if
 212                                 needed. This option specifies the file
 213                                 system access mode used when creating
 214                                 these directories. Takes an access
 215                                 mode in octal notation. Defaults to
 216                                 0755.</para></listitem>
 217                         </varlistentry>
 218
 219                         <varlistentry>
 220                                 <term><varname>TimeoutSec=</varname></term>
 221                                 <listitem><para>Configures the time to
 222                                 wait for the mount command to
 223                                 finish. If a command does not exit
 224                                 within the configured time the mount
 225                                 will be considered failed and be shut
 226                                 down again. All commands still running
 227                                 will be terminated forcibly via
 228                                 SIGTERM, and after another delay of
 229                                 this time with SIGKILL. (See
 230                                 <option>KillMode=</option> in
 231                                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
 232                                 Takes a unit-less value in seconds, or
 233                                 a time span value such as "5min
 234                                 20s". Pass 0 to disable the timeout
 235                                 logic. Defaults to
 236                                 90s.</para></listitem>
 237                         </varlistentry>
 238                 </variablelist>
 239
 240                 <para>Check
 241                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 242                 and
 243                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 244                 for more settings.</para>
 245         </refsect1>
 246
 247         <refsect1>
 248                 <title>Compatibility Options</title>
 249
 250                 <para>The following option is also available in the
 251                 <literal>[Mount]</literal> section, but exists purely
 252                 for compatibility reasons and should not be used in
 253                 newly written mount files.</para>
 254
 255                 <variablelist>
 256                         <varlistentry>
 257                                 <term><varname>FsckPassNo=</varname></term>
 258
 259                                 <listitem><para>The pass number for
 260                                 the file system checking service for
 261                                 this mount. See
 262                                 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 263                                 for more information on this setting.
 264                                 </para></listitem>
 265                         </varlistentry>
 266                 </variablelist>
 267         </refsect1>
 268
 269         <refsect1>
 270                   <title>See Also</title>
 271                   <para>
 272                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 273                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 274                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 275                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 276                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 277                           <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 278                           <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 279                           <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 280                           <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 281                   </para>
 282         </refsect1>
 283
 284 </refentry>