systemd-stable/man/systemd-sleep.conf.xml

<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

<refentry id="systemd-sleep.conf"
          xmlns:xi="http://www.w3.org/2001/XInclude">
  <refentryinfo>
    <title>systemd-sleep.conf</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemd-sleep.conf</refentrytitle>
    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemd-sleep.conf</refname>
    <refname>sleep.conf.d</refname>
    <refpurpose>Suspend and hibernation configuration file</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para><filename>/etc/systemd/sleep.conf</filename></para>
    <para><filename>/etc/systemd/sleep.conf.d/*.conf</filename></para>
    <para><filename>/run/systemd/sleep.conf.d/*.conf</filename></para>
    <para><filename>/usr/lib/systemd/sleep.conf.d/*.conf</filename></para>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><command>systemd</command> supports four general
    power-saving modes:</para>

    <variablelist>
      <varlistentry>
        <term>suspend</term>

        <listitem><para>a low-power state
        where execution of the OS is paused,
        and complete power loss might result
        in lost data, and which is fast to
        enter and exit. This corresponds to
        suspend, standby, or freeze states as
        understood by the kernel.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term>hibernate</term>

        <listitem><para>a low-power state
        where execution of the OS is paused,
        and complete power loss does not
        result in lost data, and which might
        be slow to enter and exit. This
        corresponds to the hibernation as
        understood by the kernel.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term>hybrid-sleep</term>

        <listitem><para>a low-power state
        where execution of the OS is paused,
        which might be slow to enter, and on
        complete power loss does not result in
        lost data but might be slower to exit
        in that case. This mode is called
        suspend-to-both by the kernel.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term>suspend-then-hibernate</term>

        <listitem><para>A low power state where initially user.slice unit is freezed.
        If the hardware supports low-battery alarms (ACPI _BTP), then the system is
        first suspended (the state is stored in RAM) and then hibernates if the system
        is woken up by the hardware via ACPI low-battery signal. Unit user.slice is
        thawed when system returns from hibernation. If the hardware does not support
        low-battery alarms (ACPI _BTP), then the system is suspended based on battery's
        current percentage capacity. If the current battery capacity is higher than 5%, the
        system suspends for interval calculated using battery discharge rate per hour or
        <command>HibernateDelaySec=</command>
        if former is not available.
        Battery discharge rate per hour is stored in a file which is created after
        initial suspend-resume cycle. The value is calculated using battery decreasing
        charge level over a timespan for which system was suspended. For each battery
        connected to the system, there is a unique entry. After RTC alarm wakeup from
        suspend, battery discharge rate per hour is again estimated. If the current battery
        charge level is equal to or less than 5%, the system will be hibernated (the state
        is then stored on disk) else the system goes back to suspend for the interval
        calculated using battery discharge rate per hour.
        In case of manual wakeup, if the battery was discharged while the system was
        suspended, the battery discharge rate is estimated and stored on the filesystem.
        In case the system is woken up by the hardware via the ACPI low-battery signal,
        then it hibernates.
        </para></listitem>
      </varlistentry>

    </variablelist>

    <para>Settings in these files determine what strings
    will be written to
    <filename>/sys/power/disk</filename> and
    <filename>/sys/power/state</filename> by
    <citerefentry><refentrytitle>systemd-sleep</refentrytitle><manvolnum>8</manvolnum></citerefentry>
    when
    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    attempts to suspend or hibernate the machine.
    See
    <citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>7</manvolnum></citerefentry>
    for a general description of the syntax.</para>
  </refsect1>

  <xi:include href="standard-conf.xml" xpointer="main-conf" />

  <refsect1>
    <title>Options</title>

    <para>The following options can be configured in the
    [Sleep] section of
    <filename>/etc/systemd/sleep.conf</filename> or a
    <filename>sleep.conf.d</filename> file:</para>

    <variablelist class='config-directives'>
      <varlistentry>
        <term><varname>AllowSuspend=</varname></term>
        <term><varname>AllowHibernation=</varname></term>
        <term><varname>AllowSuspendThenHibernate=</varname></term>
        <term><varname>AllowHybridSleep=</varname></term>

        <listitem><para>By default any power-saving mode is advertised if possible (i.e.
        the kernel supports that mode, the necessary resources are available). Those
        switches can be used to disable specific modes.</para>

        <para>If <varname>AllowHibernation=no</varname> or <varname>AllowSuspend=no</varname> is
        used, this implies <varname>AllowSuspendThenHibernate=no</varname> and
        <varname>AllowHybridSleep=no</varname>, since those methods use both suspend and hibernation
        internally. <varname>AllowSuspendThenHibernate=yes</varname> and
        <varname>AllowHybridSleep=yes</varname> can be used to override and enable those specific
        modes.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>SuspendMode=</varname></term>
        <term><varname>HibernateMode=</varname></term>
        <term><varname>HybridSleepMode=</varname></term>

        <listitem><para>The string to be written to
        <filename>/sys/power/disk</filename> by,
        respectively,
        <citerefentry><refentrytitle>systemd-suspend.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
        <citerefentry><refentrytitle>systemd-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, or
        <citerefentry><refentrytitle>systemd-hybrid-sleep.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
        More than one value can be specified by separating
        multiple values with whitespace. They will be tried
        in turn, until one is written without error. If
        neither succeeds, the operation will be aborted.
        </para>

        <para><citerefentry><refentrytitle>systemd-suspend-then-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        uses the value of <varname>SuspendMode=</varname> when suspending and the value of <varname>HibernateMode=</varname> when hibernating.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>SuspendState=</varname></term>
        <term><varname>HibernateState=</varname></term>
        <term><varname>HybridSleepState=</varname></term>

        <listitem><para>The string to be written to
        <filename>/sys/power/state</filename> by,
        respectively,
        <citerefentry><refentrytitle>systemd-suspend.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
        <citerefentry><refentrytitle>systemd-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, or
        <citerefentry><refentrytitle>systemd-hybrid-sleep.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
        More than one value can be specified by separating
        multiple values with whitespace. They will be tried
        in turn, until one is written without error. If
        neither succeeds, the operation will be aborted.
        </para>

        <para><citerefentry><refentrytitle>systemd-suspend-then-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        uses the value of <varname>SuspendState=</varname> when suspending and the value of <varname>HibernateState=</varname> when hibernating.
        </para></listitem>
      </varlistentry>
      <varlistentry>
        <term><varname>HibernateDelaySec=</varname></term>
        <listitem><para>The amount of time the system spends in suspend mode
        before the RTC alarm wakes the system, before the battery discharge rate
        can be estimated and used instead to calculate the suspension interval.
        <citerefentry><refentrytitle>systemd-suspend-then-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. Defaults
        to 2h.</para></listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Example: freeze</title>

    <para>Example: to exploit the <quote>freeze</quote> mode added
    in Linux 3.9, one can use <command>systemctl suspend</command>
    with
    <programlisting>[Sleep]
SuspendState=freeze</programlisting></para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>systemd-sleep</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-suspend.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-hybrid-sleep.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd-suspend-then-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>