systemd-sleep.conf(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION DIRECTORIES AND PRECEDENCE | OPTIONS | EXAMPLE: FREEZE | SEE ALSO | NOTES | COLOPHON

SYSTEMD-SLEEP.CONF(5)      systemd-sleep.conf      SYSTEMD-SLEEP.CONF(5)

NAME         top

       systemd-sleep.conf, sleep.conf.d - Suspend and hibernation
       configuration file

SYNOPSIS         top

           /etc/systemd/sleep.conf
           /etc/systemd/sleep.conf.d/*.conf
           /run/systemd/sleep.conf.d/*.conf
           /usr/lib/systemd/sleep.conf.d/*.conf

DESCRIPTION         top

       systemd supports four general power-saving modes:

       suspend
           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.

           Added in version 203.

       hibernate
           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.

           Added in version 203.

       hybrid-sleep
           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.

           Added in version 203.

       suspend-then-hibernate
           A low power state where the system is initially suspended
           (the state is stored in RAM). If the system supports
           low-battery alarms (ACPI _BTP), then the system will be woken
           up by the ACPI low-battery signal and hibernated (the state
           is then stored on disk). Also, if not interrupted within the
           timespan specified by HibernateDelaySec= or the estimated
           timespan until the system battery charge level goes down to
           5%, then the system will be woken up by the RTC alarm and
           hibernated. The estimated timespan is calculated from the
           change of the battery capacity level after the time specified
           by SuspendEstimationSec= or when the system is woken up from
           the suspend.

           Added in version 239.

       Settings in these files determine what strings will be written to
       /sys/power/disk and /sys/power/state by systemd-sleep(8) when
       systemd(1) attempts to suspend or hibernate the machine. See
       systemd.syntax(7) for a general description of the syntax.

CONFIGURATION DIRECTORIES AND PRECEDENCE         top

       The default configuration is set during compilation, so
       configuration is only needed when it is necessary to deviate from
       those defaults. The main configuration file is either in
       /usr/lib/systemd/ or /etc/systemd/ and contains commented out
       entries showing the defaults as a guide to the administrator.
       Local overrides can be created by creating drop-ins, as described
       below. The main configuration file can also be edited for this
       purpose (or a copy in /etc/ if it's shipped in /usr/) however
       using drop-ins for local configuration is recommended over
       modifications to the main configuration file.

       In addition to the "main" configuration file, drop-in
       configuration snippets are read from /usr/lib/systemd/*.conf.d/,
       /usr/local/lib/systemd/*.conf.d/, and /etc/systemd/*.conf.d/.
       Those drop-ins have higher precedence and override the main
       configuration file. Files in the *.conf.d/ configuration
       subdirectories are sorted by their filename in lexicographic
       order, regardless of in which of the subdirectories they reside.
       When multiple files specify the same option, for options which
       accept just a single value, the entry in the file sorted last
       takes precedence, and for options which accept a list of values,
       entries are collected as they occur in the sorted files.

       When packages need to customize the configuration, they can
       install drop-ins under /usr/. Files in /etc/ are reserved for the
       local administrator, who may use this logic to override the
       configuration files installed by vendor packages. Drop-ins have
       to be used to override package drop-ins, since the main
       configuration file has lower precedence. It is recommended to
       prefix all filenames in those subdirectories with a two-digit
       number and a dash, to simplify the ordering of the files. This
       also defined a concept of drop-in priority to allow distributions
       to ship drop-ins within a specific range lower than the range
       used by users. This should lower the risk of package drop-ins
       overriding accidentally drop-ins defined by users.

       To disable a configuration file supplied by the vendor, the
       recommended way is to place a symlink to /dev/null in the
       configuration directory in /etc/, with the same filename as the
       vendor configuration file.

OPTIONS         top

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

       AllowSuspend=, AllowHibernation=, AllowHybridSleep=,
       AllowSuspendThenHibernate=
           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.

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

           Added in version 240.

       HibernateMode=
           The string to be written to /sys/power/disk by
           systemd-hibernate.service(8). 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
           none of the writes succeed, the operation will be aborted.

           The allowed set of values is determined by the kernel and is
           shown in the file itself (use cat /sys/power/disk to
           display). See the kernel documentation page Basic sysfs
           Interfaces for System Suspend and Hibernation[1] for more
           details.

           systemd-suspend-then-hibernate.service(8) uses the value of
           HibernateMode= when hibernating.

           Added in version 203.

       SuspendState=
           The string to be written to /sys/power/state by
           systemd-suspend.service(8). 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
           none of the writes succeed, the operation will be aborted.

           The allowed set of values is determined by the kernel and is
           shown in the file itself (use cat /sys/power/state to
           display). See Basic sysfs Interfaces for System Suspend and
           Hibernation[1] for more details.

           systemd-suspend-then-hibernate.service(8) uses this value
           when suspending.

           Added in version 203.

       HibernateDelaySec=
           The amount of time the system spends in suspend mode before
           the system is automatically put into hibernate mode. Only
           used by systemd-suspend-then-hibernate.service(8). If the
           system has a battery, then defaults to the estimated timespan
           until the system battery charge level goes down to 5%. If the
           system has no battery, then defaults to 2h.

           Added in version 239.

       SuspendEstimationSec=
           The RTC alarm will wake the system after the specified
           timespan to measure the system battery capacity level and
           estimate battery discharging rate, which is used for
           estimating timespan until the system battery charge level
           goes down to 5%. Only used by
           systemd-suspend-then-hibernate.service(8). Defaults to 1h.

           Added in version 253.

EXAMPLE: FREEZE         top

       Example: to exploit the “freeze” mode added in Linux 3.9, one can
       use systemctl suspend with

           [Sleep]
           SuspendState=freeze

SEE ALSO         top

       systemd-sleep(8), systemd-suspend.service(8),
       systemd-hibernate.service(8), systemd-hybrid-sleep.service(8),
       systemd-suspend-then-hibernate.service(8), systemd(1),
       systemd.directives(7)

NOTES         top

        1. Basic sysfs Interfaces for System Suspend and Hibernation
           https://www.kernel.org/doc/html/latest/admin-guide/pm/sleep-states.html#basic-sysfs-interfaces-for-system-suspend-and-hibernation

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http:https://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http:https://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2023-12-22.  (At that
       time, the date of the most recent commit that was found in the
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       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       [email protected]

systemd 255                                        SYSTEMD-SLEEP.CONF(5)

Pages that refer to this page: systemd.directives(7)systemd.index(7)systemd.syntax(7)systemd-suspend.service(8)