Bug 1448306

Summary:	'virsh domjobinfo' hang while creating internal snapshot
Product:	Red Hat Enterprise Linux 7	Reporter:	yafu <yafu>
Component:	libvirt	Assignee:	Libvirt Maintainers <libvirt-maint>
Status:	CLOSED CANTFIX	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.4	CC:	dyuan, fjin, lizhu, pkrempa, rbalakri, yanqzhan, zpeng
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-05-05 07:22:37 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 yafu 2017-05-05 07:10:49 UTC

Description of problem:
  'virsh domjobinfo' hang while creating internal snapshot.

Version-Release number of selected component:
   libvirt-3.2.0-3.virtcov.el7.x86_64
   qemu-kvm-rhev-2.9.0-2.el7.x86_64

How reproducible:
   100%

Steps to Reproduce:
1.Prepare a running guest:
# virsh list
 Id    Name                           State
----------------------------------------------------
 80    rhel7.3-min                    running


2.Create internal snapshot:
#virsh snapshot-create rhel7.3-min

3.Open another terminal while doing step 2, execute 'virsh domjobinfo',the command hangs for a while then report errors:
#virsh domjobinfo rhel7.3-min
error: Timed out during operation: cannot acquire state change lock (held by remoteDispatchDomainSnapshotCreateXML)

Actual resuts:
'virsh domjobinfo' hang  while creating internal snapshot

Expected results:
'virsh domjobinfo' should not hang  while creating internal snapshot

Comment 2 Peter Krempa 2017-05-05 07:22:37 UTC

Internal snapshot ("savevm") is a synchronous command in qemu so there's no way how we could acquire any statistics, since the monitor is blocked.