Bug 963514

Summary:	Cannot create snapshot ,Unable to find cgroup for vm
Product:	Red Hat Enterprise Linux 6	Reporter:	xingxing <itxx00>
Component:	libvirt	Assignee:	Libvirt Maintainers <libvirt-maint>
Status:	CLOSED NOTABUG	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	6.4	CC:	acathrow, ajia, berrange, dyasny, dyuan, jdenemar, lsu, mzhan, shyu
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2013-05-20 10:16:42 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description xingxing 2013-05-16 03:02:58 UTC

Description of problem:
After cgconfig service restarted and libvirtd restarted ,could not create snapshot for vm.

Version-Release number of selected component (if applicable):
# uname -r
2.6.32-358.6.1.el6.x86_64
# rpm -q libvirt
libvirt-0.10.2-18.el6_4.4.x86_64
# rpm -q qemu-kvm-rhev
qemu-kvm-rhev-0.12.1.2-2.355.el6.3.x86_64


How reproducible:
100%

Steps to Reproduce:
1.service cgconfig restart
2.service libvirtd restart
3.virsh snapshot-create-as testvm s1 --disk-only
  
Actual results:
error: internal error Unable to find cgroup for cho2013051600036
in libvirtd.log:
2013-05-16 02:53:02.062+0000: 16157: error : qemuDomainSnapshotCreateDiskActive:11299 : internal error Unable to find cgroup for testvm
in /cgroup there no cgroup config for testvm.

Expected results:
create snapshot success.

Additional info:

Comment 1 xingxing 2013-05-16 03:05:36 UTC

cho2013051600036 is another vm's name ,the error message is:
error: internal error Unable to find cgroup for testvm

Comment 3 Jiri Denemark 2013-05-20 10:16:42 UTC

I don't think restarting cgconfig service is something we want to support unless there's a real reason for doing that. If you restart cgconfig service, all cgroups are removed and all tasks are moved to the root cgroup.

I'm closing this as not a bug, but feel free to reopen if there is a real situation in which cgconfig service needs to be restarted.

Comment 4 Daniel Berrangé 2013-05-20 10:27:09 UTC

If anything this is really broken behaviour of cgconfig. Nothing should ever unilaterally delete the cgroups hierarchy once the system has booted.