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NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION DIRECTORIES AND PRECEDENCE | OPTIONS | EXAMPLE: FREEZE | SEE ALSO | NOTES | COLOPHON |
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SYSTEMD-SLEEP.CONF(5) systemd-sleep.conf SYSTEMD-SLEEP.CONF(5)
systemd-sleep.conf, sleep.conf.d - Suspend and hibernation
configuration file
/etc/systemd/sleep.conf
/etc/systemd/sleep.conf.d/*.conf
/run/systemd/sleep.conf.d/*.conf
/usr/lib/systemd/sleep.conf.d/*.conf
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 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.
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.
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.
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
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[1] for more details.
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
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 the kernel documentation[1] for more details.
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. 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.
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.
Example: to exploit the “freeze” mode added in Linux 3.9, one can
use systemctl suspend with
[Sleep]
SuspendState=freeze
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)
1. the kernel documentation
https://www.kernel.org/doc/html/latest/admin-guide/pm/sleep-states.html#basic-sysfs-interfaces-for-system-suspend-and-hibernation
This page is part of the systemd (systemd system and service
manager) project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have
a bug report for this manual page, see
⟨http://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 2023-06-23. (At that
time, the date of the most recent commit that was found in the
repository was 2023-06-23.) If you discover any rendering
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
man-pages@man7.org
systemd 253 SYSTEMD-SLEEP.CONF(5)
Pages that refer to this page: systemd.directives(7), systemd.index(7), systemd.syntax(7), systemd-suspend.service(8)
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HTML rendering created 2023-06-24 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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