Bug 509799

Summary:	KVM: VM Migration fails during migration of concurrent multiple Guests,
Product:	Red Hat Enterprise Linux 5	Reporter:	Oded Ramraz <oramraz>
Component:	kvm	Assignee:	Glauber Costa <gcosta>
Status:	CLOSED WORKSFORME	QA Contact:	Lawrence Lim <llim>
Severity:	high	Docs Contact:
Priority:	high
Version:	5.4	CC:	cpelland, lihuang, rlerch, sghosh, syeghiay, tburke, tools-bugs, virt-maint, ykaul
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2009-08-30 14:21:47 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	513501

Description Oded Ramraz 2009-07-06 10:15:34 UTC

Description of problem:

Usually when running Migration of multiple Guests using VDSM migration operation done 1 by 1 ( due to semaphore in VDSM ).
There is VDSM patch which increase the number of concurrent migration to Host #CPU cores.
When running VDSM with this patch on 2 cores Host everything works fine.
After running this script with 5 concurrent 1GB VM's migrations ( vm.MigrationSourceThread.setMaxOutgoingMigrations(5)) one of the migrations has failed and VM stuck on "Migration Source" status of source and "Up" on destination.




Version-Release number of selected component (if applicable):

Host Kernel:
2.6.18-152.el5

KVM version:
kvm-83-82.el5

How reproducible:


Steps to Reproduce:
1.
2.
3.
  
Actual results:


Expected results:


Additional info:

My Host has 2 cores and 16GB Memory
Host specification:

Cores  : 2
Model  : Intel(R) Xeon(R) CPU            5150  @ 2.66GHz
Speed  : 1998

Comment 1 Dor Laor 2009-07-07 21:26:09 UTC

Can you collect the stack trace of the stuck source VM?

Comment 3 Glauber Costa 2009-07-10 16:37:58 UTC

Also, it would really help me to speak in terms of qemu, instead of vdsm here.

What is the qemu command line?

What's the output of the "info migration" command ?

Comment 4 Ludek Smid 2009-07-14 15:46:58 UTC

Release note added. If any revisions are required, please set the 
"requires_release_notes" flag to "?" and edit the "Release Notes" field accordingly.
All revisions will be proofread by the Engineering Content Services team.

New Contents:
TBD

Comment 5 Subhendu Ghosh 2009-07-14 15:48:09 UTC

Release note updated. If any revisions are required, please set the 
"requires_release_notes"  flag to "?" and edit the "Release Notes" field accordingly.
All revisions will be proofread by the Engineering Content Services team.

Diffed Contents:
@@ -1 +1 @@
-TBD+Simultaneous migration of multiple guests is not supported at this time on KVM. Migration of multiple guests should be serialized.

Comment 8 Ryan Lerch 2009-08-18 04:30:45 UTC

Release note updated. If any revisions are required, please set the 
"requires_release_notes"  flag to "?" and edit the "Release Notes" field accordingly.
All revisions will be proofread by the Engineering Content Services team.

Diffed Contents:
@@ -1 +1 @@
-Simultaneous migration of multiple guests is not supported at this time on KVM. Migration of multiple guests should be serialized.+Simultaneous migration of multiple guests is currently not supported on KVM. Migration of multiple guests should be serialized.

Comment 9 Dor Laor 2009-08-18 09:03:44 UTC

I do not think the bug related to multiple migration in parallel.
There is no such limitation. It was probably a 'regular' migration bug.
I put it on_qa since I do not think it will exist at the moment.

I'm clearing the release notes since they may just confuse users of libvirt.
Oded/Lawrence, can you test multiple migrations?

Comment 10 Dor Laor 2009-08-18 09:03:44 UTC

Deleted Release Notes Contents.

Old Contents:
Simultaneous migration of multiple guests is currently not supported on KVM. Migration of multiple guests should be serialized.