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

Provided by: systemd_252.5-2ubuntu3_amd64

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 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 HibernateDelaySec= 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.

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 RTC alarm wakes the
           system, before the battery discharge rate can be estimated and used instead to
           calculate the suspension interval.  systemd-suspend-then-hibernate.service(8).
           Defaults to 2h.

EXAMPLE: FREEZE