blockcommit --pivot does not succeed in conjunction with qemu 5.0.0

[Thomas Stein]

On 2020-05-11 08:58, Peter Krempa wrote:
> On Fri, May 08, 2020 at 13:05:01 +0200, Thomas Stein wrote:
>> 
>> Maybe:
>> 
>> from 6.3.0 release notes:
>> 
>> - qemu: Fix domain restore from a block device
>>     When using namespaces, libvirt was unable to restore a domain from 
>> a
>> block device because libvirt tried to relabel the device inside the
>> namespace while QEMU was given FD to the block device in the host.
> 
> This is not relevant to block commit in any way.

Ok, thanks for the answer. There must be another reason for my problem 
then.

cheers, t.

> 
>> 
>> cheers, t.
>> 
>> On 2020-05-08 12:48, Thomas Stein wrote:
>> > Hello one and all.
>> >
>> > Got a problem with libvirt 6.2.0 and qemu 5.0.0.
>> >
>> > virsh blockcommit mymachine vda --active --verbose --pivot
>> >
>> > works until it shows [100%] but it never actually pivots. It just sits
>> > there. Is this a known issue with 6.2.0 and i should
>> > try 6.3.0? For now i switched back to qemu 4.2.0 and this seems to
>> > solve the issue too. Any hints?
> 
> It's hard to tell from this description. It's certainly not something
> I've heard of. Both qemu-5.0 and qemu-4.2 allow libvirt to use 
> -blockdev
> way to configure disks where a lot changed compared to previous 
> versions
> but since those two versions both use blockdev it should work the same.
> 
> It kind of looks as a problem in qemu but can't tell more without debug
> logs.
> 
> Please follow the steps here https://wiki.libvirt.org/page/DebugLogs 
> and
> reproduce the bug. I can then look at the log file and see whether I 
> see
> some anomalies.