[libvirt-users] Migration problem - takes 5 minutes to start moving the memory

[Marc-Aurèle Brothier - Exoscale]

> On 01 Jun 2016, at 15:59, Daniel P. Berrange <berrange at redhat.com> wrote:
> 
> On Wed, Jun 01, 2016 at 03:55:37PM +0200, Peter Krempa wrote:
>> On Wed, Jun 01, 2016 at 11:59:29 +0200, Marc-Aurèle Brothier - Exoscale wrote:
>>> Hi,
>>> 
>>> I'm facing a strange issue while doing a migration from an hypervisor to another one. The migration takes for ever to start moving the memory.
>>> The VM had no workload what so ever, just a basic ubuntu image. The versions on the hypervisors are: libvirt 1.2.21, qemu 1.2.3
>>> 
>>> Command to launche the migration:
>>> virsh migrate --verbose --live --abort-on-error --tunnelled --p2p --auto-converge --copy-storage-inc --xml vm-6160.xml 6160  qemu+tls://<destination_hypervisor>/system
>>> 
>> 
>> You are copying storage too. It takes 5 minutes to copy the storage. The
>> memory migration starts after the storage migration converges.
> 
> I don't think that's it - if you look at the logs provided, you can see
> that the storage was apparently fully copied after 49 seconds. There was
> then 5 minutes where neither the disk or memory processed numbers
> increased, before memory copying started. So there's something fishy
> going on there, whether just bogus stats reporting by qemu or a genuine
> delay/hang somewhere
> 

That's correct, the disk was copied pretty quickly and I could see it at the destination growing during those 49 seconds. What would you do to try to figure out what's going on?

Correction, we are using Qemu 2.3 (not 1.2.3, the Ubuntu syntaxe confised me with 1:2.3)