Manual: systemd-hibernate-resume

SYSTEMD-HIBERNATE-RESUME.SERVICE(8)   systemd-hibernate-resume.service	 SYSTEMD-HIBERNATE-RESUME.SERVICE(8)

NAME
       systemd-hibernate-resume.service, systemd-hibernate-clear.service, systemd-hibernate-resume - Resume
       from hibernation

SYNOPSIS
       systemd-hibernate-resume.service

       systemd-hibernate-clear.service

       /usr/lib/systemd/systemd-hibernate-resume

DESCRIPTION
       systemd-hibernate-resume.service initiates the resume from hibernation.

       systemd-hibernate-resume only supports the in-kernel hibernation implementation, see Swap suspend[1].
       Internally, it works by writing the major:minor of selected device node to /sys/power/resume, along
       with the offset in memory pages (/sys/power/resume_offset) if supported.

       The resume device node is either passed directly through arguments, or automatically acquired from
       kernel command line options and/or HibernateLocation EFI variable. The latter will normally be
       cleared by systemd-hibernate-resume.service on resumption. If a stale variable is detected, it would
       be cleared by systemd-hibernate-clear.service.

       Failing to initiate a resume is not an error condition. It may mean that there was no resume image
       (e. g. if the system has been simply powered off and not hibernated). In such cases, the boot is
       ordinarily continued.

SEE ALSO
       systemd(1), systemd-hibernate-resume-generator(8)

NOTES
	1. Swap suspend
	   https://docs.kernel.org/power/swsusp.html

systemd 259.5								 SYSTEMD-HIBERNATE-RESUME.SERVICE(8)