Bug 2322467

Summary:	System fails to boot, cgroup v1
Product:	[Fedora] Fedora	Reporter:	Wyatt Childers <rhbugs.2o67n>
Component:	systemd	Assignee:	systemd-maint
Status:	CLOSED NOTABUG	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	urgent	Docs Contact:
Priority:	unspecified
Version:	41	CC:	daan.j.demeyer, fedoraproject, lnykryn, msekleta, ryncsn, suraj.ghimire7, systemd-maint, yuwatana, zbyszek
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Hardware:	x86_64
OS:	Linux
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Last Closed:	2024-10-30 08:08:07 UTC	Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description Wyatt Childers 2024-10-29 15:39:06 UTC

The system fails to boot following updating to Fedora 41 reporting that cgroupv1 is no longer supported.

I do not recall ever explicitly modifying my boot flags to modify anything with cgroups. However, systemd.unified_cgroup_hierarchy=0 was present on my boot flags and this resulted in a failure to boot following the Fedora 41 update.

Reproducible: Always

Comment 1 Wyatt Childers 2024-10-29 15:40:46 UTC

If there was a last minute update that went out that should've fixed this within the last 24 hours, this might be my fault. I did not check for updates again having installed updates fairly late last night.

I'm kind of skeptical that's the case however. More likely, since this is an older install (I think originally Fedora 30?) it's something that's built up over the years and resulted in a breakage.

Comment 2 Wyatt Childers 2024-10-29 15:48:01 UTC

For anyone that may be bumping into this themselves. I fixed by editing the boot arguments in grub and removing "systemd.unified_cgroup_hierarchy=0".

After the computer was up and running, I then removed "systemd.unified_cgroup_hierarchy=0" from "/etc/default/grub" and then ran "sudo grub2-mkconfig -o /boot/grub2/grub.cfg" to fix the boot loader for future boots.

Comment 3 Lukáš Nykrýn 2024-10-30 08:08:07 UTC

Yeah, now we dropped the support of cgroups v1. But I don't think we've ever put automatically systemd.unified_cgroup_hierarchy=0 to kernel cmdline. But at one point, it was necessary to set it if you wanted to run docker. Anyway, I don't see any issues here on our side, so let's close this.

Comment 4 Wyatt Childers 2024-10-30 16:23:49 UTC

Aha! That makes a lot of sense, I almost definitely did add that many years ago for Docker reasons.