[libvirt-users] QemuDomainObjEndJob called when libvirtd is started and libvirt insists qemu is using the wrong disk source.

[Laine Stump]

On 04/28/2015 09:21 PM, Matthew Schumacher wrote:
> On 04/28/2015 05:13 PM, Laine Stump wrote:
>> Bah. Your debug symbols aren't enough to give a full stack trace - what
>> I was really looking for was those things marked as ??.
>>
>> However, your debug output shows several things leading up tothe
>> qemuProcessStop that might have been the reason for it being called:
>>
>> 1) virStorageFileBackendFileReadHeader() complains that there is no
>> medium in /dev/sr0 (i.e. no disk in the CD drive) (this was actually in
>> your much more abbreviated log in an earlier message, but for some
>> reason I skipped over it :-/)
>>
>> 2) libvirt sends the following command to qemu:
>>
>>   
>> {"execute":"block-commit","arguments":{"device":"bogus"},"id":"libvirt-4"}
>>
>>  and gets back this error:
>>
>>    {"id": "libvirt-4",
>>    "error": {"class": "DeviceNotFound", "desc": "Device 'bogus' not found"}}
>>
>> Since (1) actually generates a libvirt error log, that is what I would
>> look into first.
>>
> Thanks Laine,
>
> Confirmed, if I:
>
> virsh attach-disk test '' hdc --type cdrom
>
> Then I can kick libvirtd all I want and it doesn't take out my domain.
>
> So now that that is fixed, I'm back to trying to figure out out why
> blockcopy --wait won't actually wait, as it's hard to migrate domains
> from one storage to another while needing to continually call blockjob
> to see if we are 100% mirroring.
>
> I posted plenty of debug here:
> https://bugzilla.redhat.com/attachment.cgi?id=1019911


That is an attachment to:

  https://bugzilla.redhat.com/show_bug.cgi?id=1210903

and it looks like Eric noticed it and has commented in the bug.


>
> I wonder if the issue isn't obvious to you since you know a bit more
> about how libvirt interacts with qemu than I do.


Nope. I am ignorant about all the new block operations, but if Eric is
on the case you're in good hands.


> Also, is there a link so some documentation that describes all of the
> json going between libvirt and qemu?

If there is, I guess it would be somewhere in qemu documentation, maybe
on linux-kvm.org?