Provided by: systemd_249.11-0ubuntu3.12_amd64 bug

NAME

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

SYNOPSIS

       /etc/systemd/sleep.conf

       /etc/systemd/sleep.conf.d/*.conf

       /run/systemd/sleep.conf.d/*.conf

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

DESCRIPTION

       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.

       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.

       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.

       suspend-then-hibernate
           A low power state where the system is initially suspended (the state is stored in RAM). If not
           interrupted within the delay specified by HibernateDelaySec=, the system will be woken using an RTC
           alarm and hibernated (the state is then stored on disk).

       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

       The default configuration is set during compilation, so configuration is only needed when it is necessary
       to deviate from those defaults. Initially, the main configuration file in /etc/systemd/ contains
       commented out entries showing the defaults as a guide to the administrator. Local overrides can be
       created by editing this file or by creating drop-ins, as described below. 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.

       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

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

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

       SuspendMode=, HibernateMode=, HybridSleepMode=
           The string to be written to /sys/power/disk by, respectively, systemd-suspend.service(8), systemd-
           hibernate.service(8), or systemd-hybrid-sleep.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 neither succeeds, the operation will be aborted.

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

       SuspendState=, HibernateState=, HybridSleepState=
           The string to be written to /sys/power/state by, respectively, systemd-suspend.service(8), systemd-
           hibernate.service(8), or systemd-hybrid-sleep.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 neither succeeds, the operation will be aborted.

           systemd-suspend-then-hibernate.service(8) uses the value of SuspendState= when suspending and the
           value of HibernateState= when hibernating.

       HibernateDelaySec=
           The amount of time the system spends in suspend mode before the system is automatically put into
           hibernate mode, when using systemd-suspend-then-hibernate.service(8). Defaults to 2h.

EXAMPLE: FREEZE

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

           [Sleep]
           SuspendState=freeze

SEE ALSO

       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)