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. Note that the User= and Group= options are
  79                 not particularly useful for mount units specifying a
  80                 <literal>Type=</literal> option or using configuration
  81                 not specified in <filename>/etc/fstab</filename>;
  82                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  83                 will refuse options that aren't listed in
  84                 <filename>/etc/fstab</filename> if it is not run as
  85                 UID 0.</para>
  86
  87                 <para>Mount units must be named after the mount point
  88                 directories they control. Example: the mount point
  89                 <filename>/home/lennart</filename> must be configured
  90                 in a unit file
  91                 <filename>home-lennart.mount</filename>. For details
  92                 about the escaping logic used to convert a file system
  93                 path to a unit name see
  94                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
  95
  96                 <para>Optionally, a mount unit may be accompanied by
  97                 an automount unit, to allow on-demand or parallelized
  98                 mounting. See
  99                 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 100
 101                 <para>If a mount point is beneath another mount point
 102                 in the file system hierarchy, a dependency between both
 103                 units is created automatically.</para>
 104
 105                 <para>Mount points created at runtime independent on
 106                 unit files or <filename>/etc/fstab</filename> will be
 107                 monitored by systemd and appear like any other mount
 108                 unit in systemd.</para>
 109         </refsect1>
 110
 111         <refsect1>
 112                 <title><filename>/etc/fstab</filename></title>
 113
 114                 <para>Mount units may either be configured via unit
 115                 files, or via <filename>/etc/fstab</filename> (see
 116                 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 117                 for details). Mounts listed in
 118                 <filename>/etc/fstab</filename> will be converted into
 119                 native units dynamically at boot and when the
 120                 configuration of the system manager is reloaded. See
 121                 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 122                 for details about the conversion.</para>
 123
 124                 <para>When reading <filename>/etc/fstab</filename> a
 125                 few special mount options are understood by systemd
 126                 which influence how dependencies are created for mount
 127                 points from <filename>/etc/fstab</filename>. systemd
 128                 will create a dependency of type
 129                 <option>Wants</option> from either
 130                 <filename>local-fs.target</filename> or
 131                 <filename>remote-fs.target</filename>, depending
 132                 whether the file system is local or remote. If
 133                 <option>x-systemd.automount</option> is set, an
 134                 automount unit will be created for the file
 135                 system. See
 136                 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 137                 for details. If
 138                 <option>x-systemd.device-timeout=</option> is
 139                 specified it may be used to configure how long systemd
 140                 should wait for a device to show up before giving up
 141                 on an entry from
 142                 <filename>/etc/fstab</filename>. Specify a time in
 143                 seconds or explicitly specify a unit as
 144                 <literal>s</literal>, <literal>min</literal>,
 145                 <literal>h</literal>, <literal>ms</literal>.</para>
 146
 147                 <para>If a mount point is configured in both
 148                 <filename>/etc/fstab</filename> and a unit file, the
 149                 configuration in the latter takes precedence.</para>
 150         </refsect1>
 151
 152         <refsect1>
 153                 <title>Options</title>
 154
 155                 <para>Mount files must include a [Mount] section,
 156                 which carries information about the file system mount points it
 157                 supervises. A number of options that may be used in
 158                 this section are shared with other unit types. These
 159                 options are documented in
 160                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 161                 and
 162                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
 163                 options specific to the [Mount] section of mount
 164                 units are the following:</para>
 165
 166                 <variablelist>
 167
 168                         <varlistentry>
 169                                 <term><varname>What=</varname></term>
 170                                 <listitem><para>Takes an absolute path
 171                                 of a device node, file or other
 172                                 resource to mount. See
 173                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 174                                 for details. If this refers to a
 175                                 device node, a dependency on the
 176                                 respective device unit is
 177                                 automatically created. (See
 178                                 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.)
 179                                 This option is
 180                                 mandatory.</para></listitem>
 181                         </varlistentry>
 182
 183                         <varlistentry>
 184                                 <term><varname>Where=</varname></term>
 185                                 <listitem><para>Takes an absolute path
 186                                 of a directory of the mount point. If
 187                                 the mount point does not exist at the
 188                                 time of mounting, it is created. This
 189                                 string must be reflected in the unit
 190                                 file name. (See above.) This option is
 191                                 mandatory.</para></listitem>
 192                         </varlistentry>
 193
 194                         <varlistentry>
 195                                 <term><varname>Type=</varname></term>
 196                                 <listitem><para>Takes a string for the
 197                                 filesystem type. See
 198                                 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 199                                 for details. This setting is
 200                                 optional.</para></listitem>
 201                         </varlistentry>
 202
 203                         <varlistentry>
 204                                 <term><varname>Options=</varname></term>
 205
 206                                 <listitem><para>Mount options to use
 207                                 when mounting. This takes a comma
 208                                 separated list of options. This
 209                                 setting is optional.</para></listitem>
 210                         </varlistentry>
 211
 212                         <varlistentry>
 213                                 <term><varname>DirectoryMode=</varname></term>
 214                                 <listitem><para>Directories of mount
 215                                 points (and any parent directories)
 216                                 are automatically created if
 217                                 needed. This option specifies the file
 218                                 system access mode used when creating
 219                                 these directories. Takes an access
 220                                 mode in octal notation. Defaults to
 221                                 0755.</para></listitem>
 222                         </varlistentry>
 223
 224                         <varlistentry>
 225                                 <term><varname>TimeoutSec=</varname></term>
 226                                 <listitem><para>Configures the time to
 227                                 wait for the mount command to
 228                                 finish. If a command does not exit
 229                                 within the configured time the mount
 230                                 will be considered failed and be shut
 231                                 down again. All commands still running
 232                                 will be terminated forcibly via
 233                                 SIGTERM, and after another delay of
 234                                 this time with SIGKILL. (See
 235                                 <option>KillMode=</option> in
 236                                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
 237                                 Takes a unit-less value in seconds, or
 238                                 a time span value such as "5min
 239                                 20s". Pass 0 to disable the timeout
 240                                 logic. Defaults to
 241                                 90s.</para></listitem>
 242                         </varlistentry>
 243                 </variablelist>
 244
 245                 <para>Check
 246                 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 247                 and
 248                 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 249                 for more settings.</para>
 250         </refsect1>
 251
 252         <refsect1>
 253                 <title>Compatibility Options</title>
 254
 255                 <para>The following option is also available in the
 256                 <literal>[Mount]</literal> section, but exists purely
 257                 for compatibility reasons and should not be used in
 258                 newly written mount files.</para>
 259
 260                 <variablelist>
 261                         <varlistentry>
 262                                 <term><varname>FsckPassNo=</varname></term>
 263
 264                                 <listitem><para>The pass number for
 265                                 the file system checking service for
 266                                 this mount. See
 267                                 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 268                                 for more information on this setting.
 269                                 </para></listitem>
 270                         </varlistentry>
 271                 </variablelist>
 272         </refsect1>
 273
 274         <refsect1>
 275                   <title>See Also</title>
 276                   <para>
 277                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 278                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 279                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 280                           <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 281                           <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 282                           <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 283                           <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 284                           <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 285                           <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 286                   </para>
 287         </refsect1>
 288
 289 </refentry>