Bug 683478

Summary:	RFE: support soft reboot to reduce server downtime
Product:	Red Hat Enterprise Linux 7	Reporter:	Lubos Kocman <lkocman>
Component:	systemd	Assignee:	systemd-maint
Status:	CLOSED NEXTRELEASE	QA Contact:	qe-baseos-daemons
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	7.0	CC:	notting, systemd-maint-list, yossig
Target Milestone:	rc	Keywords:	FutureFeature
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-06-21 21:00:19 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description Lubos Kocman 2011-03-09 14:22:36 UTC

Description of problem:

Sol11Express / OpenIndiana already support soft reboot. Which allows you to reboot machine without entering grub or POST.

This is killer feature as some servers are spending most boot time in self checks or raid initialization-configuration.

Solaris is using beadm to specify target that will be active on reboot.

See reboot vs reboot -p in OpenIndiana / Solaris 11 Express

It would be really killer feature for our customers.

It could save around 5+ minutes on boot time in on lot of cases (depends on grub configuration and average length of POST).

Comment 1 Lubos Kocman 2011-03-09 14:25:33 UTC

It should be such difficult to combine reboot with kexec and other code.

Comment 4 Lennart Poettering 2013-06-21 21:00:19 UTC

We already have that in systemd in RHEL7. Install "kexec-tools" and try "systemctl kexec".

Comment 5 yossig 2015-08-03 10:30:28 UTC

Hi,

Just came by this entry.  Seems the last note from 2013 is incorrect.
It does bring the system down fast, but goes to BIOS.

using kexec, one can load kernel/initrd and jump over to start the o/s without going to Bios.  I've done this via a small shell script I wrote, getting the information from Grub's config, but systemctl kexec does not do the trick just yet.

-Yossi