Re: [Qemu-discuss] [Qemu-devel] KVM guest gets aborted if blockcommit is called

[Eric Blake]

On 08/27/2015 02:01 PM, Christian Rößner wrote:

>>>>
>>>> I think  you may be running into a bug that is fixed by a recent patch
>>>> (after v2.4.0): 
>>>>
>>>> commit e424aff5f307227b1c2512bbb8ece891bb895cef
>>>> Author: Kevin Wolf <address@hidden>
>>>> Date:   Thu Aug 13 10:41:50 2015 +0200
>>>>
>>>>   mirror: Fix coroutine reentrance
>>>>
>>>>
>>>> Could you retry with qemu.git/master, and see if that fixes the issue
>>>> you are seeing?
>>>
>>> Until now, everything looks perfectly. No issues. Backup is running 
>>> smoothly.
>>>
>>> Thanks very much. If nothing changes until tonight, I am going to close the 
>>> bug report.
>>>
>>
>> Christian,
>>
>> Great to hear, thanks for the follow-up.
> 
> Just a final result:
> 
> As I use libvirt with qemu, I used the blockcommit feature with libvirt. 
> Running blockcommit directly with --wait --active --pivot, it may happen that 
> the pivot fails, because the blockcommit wasn't already ready to pivot. But I 
> do not know, if this is libvirt related or qemu. Splitting it into 
> blockcommit and blockjob, everything works like a charm. So I have a working 
> solution now. Thanks very much for your help and feedback.

Which version of libvirt? There was a bug up until 1.2.18 where older
libvirt got thrown off by newer qemu returning a status with 0 progress
but equal to the block job size, and libvirt interpreting it as job
complete with a result of failing the command; splitting the job into
distinct parts was indeed the right workaround as it prevented hitting
the window.  See libvirt commit eae5924

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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