systemd-hibernate-resume.service, systemd-hibernate-clear.service, systemd-hibernate-resume — Resume from hibernation
systemd-hibernate-resume.service
systemd-hibernate-clear.service
/usr/lib/systemd/systemd-hibernate-resume
systemd-hibernate-resume.service
initiates the resume from hibernation.
systemd-hibernate-resume only supports the in-kernel hibernation
implementation, see Swap suspend.
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.