man/systemd-suspend.service.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   8   Copyright 2012 Lennart Poettering
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  23
  24 <refentry id="systemd-suspend.service">
  25
  26         <refentryinfo>
  27                 <title>systemd-suspend.service</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-suspend.service</refentrytitle>
  42                 <manvolnum>8</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd-suspend.service</refname>
  47                 <refname>systemd-hibernate.service</refname>
  48                 <refname>systemd-hybrid-sleep.service</refname>
  49                 <refname>systemd-sleep</refname>
  50                 <refpurpose>System sleep state logic</refpurpose>
  51         </refnamediv>
  52
  53         <refsynopsisdiv>
  54                 <para><filename>systemd-suspend.service</filename></para>
  55                 <para><filename>systemd-hibernate.service</filename></para>
  56                 <para><filename>systemd-hybrid-sleep.service</filename></para>
  57                 <para><filename>/usr/lib/systemd/systemd-sleep</filename></para>
  58         </refsynopsisdiv>
  59
  60         <refsect1>
  61                 <title>Description</title>
  62
  63                 <para><filename>systemd-suspend.service</filename> is
  64                 a system service that is pulled in by
  65                 <filename>suspend.target</filename> and is responsible
  66                 for the actual system suspend. Similar,
  67                 <filename>systemd-hibernate.service</filename> is
  68                 pulled in by <filename>hibernate.target</filename> to
  69                 execute the actual hibernation. Finally,
  70                 <filename>systemd-hybrid-sleep.service</filename> is
  71                 pulled in by <filename>hybrid-sleep.target</filename>
  72                 to execute hybrid hibernation with system
  73                 suspend.</para>
  74
  75                 <para>Immediately before entering system suspend
  76                 and/or hibernation
  77                 <filename>systemd-suspend.service</filename> (and the
  78                 other mentioned units, respectively) will run all
  79                 executables in
  80                 <filename>/usr/lib/systemd/system-sleep/</filename>
  81                 and pass two arguments to them. The first argument
  82                 will be "<literal>pre</literal>", the second either
  83                 "<literal>suspend</literal>",
  84                 "<literal>hibernate</literal>", or
  85                 "<literal>hybrid-sleep</literal>" depending on the
  86                 chosen action. Immediately after leaving system
  87                 suspend and/or hibernation the same executables are run,
  88                 but the first argument is now
  89                 "<literal>post</literal>". All executables in this
  90                 directory are executed in parallel, and execution of
  91                 the action is not continued before all executables
  92                 finished.</para>
  93
  94                 <para>Note that scripts or binaries dropped in
  95                 <filename>/usr/lib/systemd/system-sleep/</filename>
  96                 are intended for local use only and should be
  97                 considered hacks. If applications want to be notified
  98                 of system suspend/hibernation and resume there are
  99                 much nicer interfaces available.</para>
 100
 101                 <para>Note that
 102                 <filename>systemd-suspend.service</filename>,
 103                 <filename>systemd-hibernate.service</filename> and
 104                 <filename>systemd-hybrid-sleep.service</filename>
 105                 should never be executed directly. Instead, trigger
 106                 system sleep states with a command such as
 107                 "<literal>systemctl suspend</literal>" or
 108                 similar.</para>
 109
 110                 <para>Internally, this service will echo a string like
 111                 <literal>mem</literal> into
 112                 <filename>/sys/power/state</filename>, to trigger the
 113                 actual system suspend.</para>
 114         </refsect1>
 115
 116         <refsect1>
 117                 <title>See Also</title>
 118                 <para>
 119                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 120                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 121                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 122                         <citerefentry><refentrytitle>systemd-halt.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 123                 </para>
 124         </refsect1>
 125
 126 </refentry>