man/systemd-hibernate-resume.service.xml

   1 <?xml version="1.0"?>
   2 <!--*-nxml-*-->
   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   4   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
   5 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   6 <refentry id="systemd-hibernate-resume.service" conditional='ENABLE_HIBERNATE'>
   7
   8   <refentryinfo>
   9     <title>systemd-hibernate-resume.service</title>
  10     <productname>systemd</productname>
  11   </refentryinfo>
  12
  13   <refmeta>
  14     <refentrytitle>systemd-hibernate-resume.service</refentrytitle>
  15     <manvolnum>8</manvolnum>
  16   </refmeta>
  17
  18   <refnamediv>
  19     <refname>systemd-hibernate-resume.service</refname>
  20     <refname>systemd-hibernate-clear.service</refname>
  21     <refname>systemd-hibernate-resume</refname>
  22     <refpurpose>Resume from hibernation</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <para><filename>systemd-hibernate-resume.service</filename></para>
  27     <para><filename>systemd-hibernate-clear.service</filename></para>
  28     <para><filename>/usr/lib/systemd/systemd-hibernate-resume</filename></para>
  29   </refsynopsisdiv>
  30
  31   <refsect1>
  32     <title>Description</title>
  33
  34     <para><filename>systemd-hibernate-resume.service</filename> initiates the resume from hibernation.</para>
  35
  36     <para><command>systemd-hibernate-resume</command> only supports the in-kernel hibernation
  37     implementation, see <ulink url="https://docs.kernel.org/power/swsusp.html">Swap suspend</ulink>.
  38     Internally, it works by writing the major:minor of selected device node to
  39     <filename>/sys/power/resume</filename>, along with the offset in memory pages
  40     (<filename>/sys/power/resume_offset</filename>) if supported.</para>
  41
  42     <para>The resume device node is either passed directly through arguments, or automatically acquired
  43     from kernel command line options and/or <varname>HibernateLocation</varname> EFI variable. The latter
  44     will normally be cleared by <filename>systemd-hibernate-resume.service</filename> on resumption.
  45     If a stale variable is detected, it would be cleared by
  46     <filename>systemd-hibernate-clear.service</filename>.</para>
  47
  48     <para>Failing to initiate a resume is not an error condition. It may mean that there was
  49     no resume image (e. g. if the system has been simply powered off and not hibernated).
  50     In such cases, the boot is ordinarily continued.</para>
  51   </refsect1>
  52
  53   <refsect1>
  54     <title>See Also</title>
  55     <para><simplelist type="inline">
  56       <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
  57       <member><citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
  58     </simplelist></para>
  59   </refsect1>
  60
  61 </refentry>