SLEEP.CONF(5)

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

SYNOPSIS

/etc/elogind/sleep.conf

/etc/elogind/sleep.conf.d/*.conf

/run/elogind/sleep.conf.d/*.conf

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

DESCRIPTION

elogind 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, /sys/power/mem_sleep and /sys/power/state by elogind(8) when loginctl(1) attempts to suspend or hibernate the machine.

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. The main configuration file is loaded from one of the listed directories in order of priority, only the first file found is used: /etc/elogind/, /run/systemd/, /usr/local/lib/elogind/ [1], /usr/lib/elogind/. The vendor version of the file contains commented out entries showing the defaults as a guide to the administrator. Local overrides can also 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 is shipped under /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. This also defines a concept of drop-in priorities to allow OS vendors 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. It is recommended to use the range 10-40 for drop-ins in /usr/ and the range 60-90 for drop-ins in /etc/ and /run/, to make sure that local and transient drop-ins take priority over drop-ins shipped by the OS vendor.

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/elogind/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.

SuspendMode=, HibernateMode=
    The string to be written to /sys/power/disk is taken from HibernateMode= when hibernating, the string to be written to /sys/power/mem_sleep is taken from SuspendMode= when suspending with elogind(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 and cat /sys/power/mem_sleep to display). See the kernel documentation page Basic sysfs Interfaces for System Suspend and Hibernation[2] for more details.

    When doing suspend-then-hibernate elogind(8) uses the value of SuspendMode= when suspending and the value of HibernateMode= when hibernating.

    Added in version 203.

SuspendState=
    The string to be written to /sys/power/state by elogind(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[2] for more details.

    elogind(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 elogind(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 elogind(8) with suspend-then-hibernate. Defaults to 1h.

    Added in version 253.

AllowPowerOffInterrupts=, AllowSuspendInterrupts=
    Allow hook scripts to interrupt a poweroff operation by setting "AllowPowerOffInterrupts" to "yes" and/or to interrupt a sleep operation by setting "AllowSuspendInterrupts" to "yes". The default value is "no". Please see loginctl(1) for more information about hook scripts.

BroadcastPowerOffInterrupts=, BroadcastSuspendInterrupts=
    By default an interrupt of a power off or a suspend is broadcasted. If you do not whish these broadcasts to happen, change "BroadcastPowerOffInterrupts" and/or "BroadcastSuspendInterrupts" to "no" in /etc/elogind/sleep.conf. Please see loginctl(1) for more information about hook scripts.

HandleNvidiaSleep=
    If you have an Nvidia graphics card that needs an old driver which does not yet install its own hook script like /lib/elogind/system-sleep/nvidia or similar, you might set "HandleNvidiaSleep" to "yes" in /etc/elogind/sleep.conf to have elogind try to suspend/hibernate your Nvidia graphics card. Please note that this can only work if your nvidia kernel module was loaded with the "NVreg_PreserveVideoMemoryAllocations" module option set to "1". Also please do not set "HandleNvidiaSleep" to "yes" if the driver has installed a hook script, as the script will always be executed.

SuspendByUsing=, HibernateByUsing=
    Instead of writing the corresponding state to /sys/power/state, an executable can be defined to call instead. More than one value can be specified by separating multiple values with whitespace. They will be tried in turn, until one is called without error. If neither succeeds, the default operation of writing to /sys/power/state is performed.

EXAMPLE: FREEZE

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

    [Sleep]
    SuspendState=freeze

SEE ALSO

elogind(8), loginctl(1)

NOTES

1.  💣💥🧨💥💥💣 Please note that those configuration files must be available at all times. If /usr/local/ is a separate partition, it may not be available during early boot, and must not be used for configuration.

2.  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