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Bug 1301860

Summary: vCPU offline hang in real-time guest
Product: Red Hat Enterprise Linux 7 Reporter: Peter Xu <peterx>
Component: qemu-kvm-rhevAssignee: Peter Xu <peterx>
Status: CLOSED NOTABUG QA Contact: Pei Zhang <pezhang>
Severity: medium Docs Contact:
Priority: medium    
Version: 7.3CC: daolivei, hhuang, huding, juzhang, michen, pagupta, peterx, pezhang, virt-maint, xfu
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2017-10-11 04:42:46 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:

Comment 3 Daniel Bristot de Oliveira 2016-02-03 19:34:47 UTC 
Hi Peter,

There are some known hotplug issues on kernel-rt. For an example, see BZ1267425.

On this BZ I was able to identify the root cause by inspecting a
vmcore, and on these cases, the vmcore is the best tool to understand
why the system hanged.

Can you please capture a vmcore of the VM after it hangs on hotplug
operations?

Here is a document from support explaining how to capture a vmcore of a VM:

https://access.redhat.com/solutions/39604

We will also need the debuginfo packages of the kernel that was running
on the VM.
Comment 6 Pei Zhang 2017-10-11 04:04:13 UTC 
Peter, this issue has gone with rhel7.5. 


After online/offline 100 times using script in Description, both host and guest work well, not any error.

Versions:
3.10.0-730.rt56.658.el7.x86_64
qemu-kvm-rhev-2.10.0-1.el7.x86_64
libvirt-3.7.0-2.el7.x86_64
tuned-2.8.0-5.el7.noarch


Best Regards,
Pei
Comment 7 Peter Xu 2017-10-11 04:42:46 UTC 
(In reply to Pei Zhang from comment #6)
> Peter, this issue has gone with rhel7.5. 
> 
> 
> After online/offline 100 times using script in Description, both host and
> guest work well, not any error.
> 
> Versions:
> 3.10.0-730.rt56.658.el7.x86_64
> qemu-kvm-rhev-2.10.0-1.el7.x86_64
> libvirt-3.7.0-2.el7.x86_64
> tuned-2.8.0-5.el7.noarch
> 
> 
> Best Regards,
> Pei

Thanks Pei!  Then I'm closing the bug.

Peter