sleep.conf

elogind
sleep.conf 5
sleep.conf sleep.conf.d Suspend and hibernation configuration file

`/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.

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

## 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.

`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 for more details.

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

`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 for more details.

  elogind 8 uses this value when suspending.

`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.

`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.

`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