man/systemd.unit.xml

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  23
  24 <refentry id="systemd.unit">
  25
  26         <refentryinfo>
  27                 <title>systemd.unit</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.unit</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.unit</refname>
  47                 <refpurpose>systemd unit configuration files</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.service</filename></para>
  52                 <para><filename>systemd.socket</filename></para>
  53                 <para><filename>systemd.device</filename></para>
  54                 <para><filename>systemd.mount</filename></para>
  55                 <para><filename>systemd.automount</filename></para>
  56                 <para><filename>systemd.swap</filename></para>
  57                 <para><filename>systemd.target</filename></para>
  58                 <para><filename>systemd.path</filename></para>
  59                 <para><filename>systemd.timer</filename></para>
  60         </refsynopsisdiv>
  61
  62         <refsect1>
  63                 <title>Description</title>
  64
  65                 <para>A unit configuration file encodes information
  66                 about a service, a socket, a device, a mount point, an
  67                 automount point, a swap file or patition, a start-up
  68                 target, a file system path or a timer controlled and
  69                 supervised by <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>. The syntax is inspired by XDG
  70                 <filename>.desktop</filename> files, which are in turn
  71                 inspired by Microsoft Windows <filename>.ini</filename>
  72                 files.</para>
  73
  74                 <para>This man pages lists the common configuration
  75                 options of the all unit types. These options need to
  76                 be configured either in the [Unit] resp. [Install]
  77                 section of the unit files.</para>
  78         </refsect1>
  79
  80         <refsect1>
  81                 <title>Options</title>
  82
  83                 <para>Unit file may include a [Unit] section, which
  84                 carries generic information about the unit that is not
  85                 dependent on the type of unit:</para>
  86
  87                 <variablelist>
  88                         <varlistentry>
  89                                 <term><varname>Names=</varname></term>
  90
  91                                 <listitem><para>Additional names for
  92                                 this unit. The names listed here must
  93                                 have the same suffix (i.e. type) as
  94                                 the unit file name. This option may be
  95                                 specified more than once, in which
  96                                 case all listed names are used. Note
  97                                 that this option is different from the
  98                                 <varname>Alias=</varname> option from
  99                                 the [Install] section mentioned
 100                                 below. See below for details</para>
 101                                 </listitem>
 102                         </varlistentry>
 103                         <varlistentry>
 104                                 <term><varname>Requires=</varname></term>
 105
 106                                 <listitem><para>Requirement
 107                                 dependencies on other units. If this
 108                                 units get activated the units listed
 109                                 here will be activated as well. If one
 110                                 of the other units gets deactivated or
 111                                 its activation fails, this unit will
 112                                 be deactivated. This option may be
 113                                 specified more than once, in which
 114                                 case requirement dependencies for all
 115                                 listed names are created.</para>
 116                                 </listitem>
 117                         </varlistentry>
 118                 </variablelist>
 119
 120                 <para>Unit file may include a [Install] section, which
 121                 carries installation information for the unit. This
 122                 section is not interpreted by
 123                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 124                 during runtime. It is used exclusively by the
 125                 <citerefentry><refentrytitle>systemd-install</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 126                 during installation of a unit:</para>
 127
 128                 <variablelist>
 129                         <varlistentry>
 130                                 <term><varname>Alias=</varname></term>
 131
 132                                 <listitem><para>Additional names this
 133                                 unit shall be installed under. The
 134                                 names listed here must have the same
 135                                 suffix (i.e. type) as the unit file
 136                                 name. This option may be specified
 137                                 more than once, in which case all
 138                                 listed names are used. At installation
 139                                 time
 140                                 <command>systemd-install</command>
 141                                 will create symlinks from these names
 142                                 to the unit file name. Note that this
 143                                 is different from the
 144                                 <varname>Names=</varname> option from
 145                                 the [Unit] section mentioned above:
 146                                 The names from
 147                                 <varname>Names=</varname> apply
 148                                 unconditionally if the unit is
 149                                 loaded. The names from
 150                                 <varname>Alias=</varname> apply only
 151                                 if the unit is actually installed with
 152                                 the <command>systemd-install</command>
 153                                 tool.  Also, if systemd searches for a
 154                                 unit, it will discover symlinked alias
 155                                 names, but not names configured only
 156                                 with <varname>Names=</varname>. It is
 157                                 a common pattern to list a name in both
 158                                 options. In this case, a unit will be
 159                                 active under all names if installed,
 160                                 but also if not installed but
 161                                 requested
 162                                 explicitly.</para></listitem>
 163                         </varlistentry>
 164                 </variablelist>
 165
 166         </refsect1>
 167
 168         <refsect1>
 169                 <title>See Also</title>
 170                 <para>
 171                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 172                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 173                         <citerefentry><refentrytitle>systemd-install</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 174                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 175                         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 176                         <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 177                         <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 178                         <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 179                         <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 180                         <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 181                         <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 182                         <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 183                         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 184                 </para>
 185         </refsect1>
 186
 187 </refentry>