Open Stack

Sean;

This is Victoria.  I was trying to migrate from a CentOS 8 (libvirt 6.6.0) to a Ubuntu 20.04 (libvirt 6.0.0).

I may not have any logs from it, as I've wiped out the host OS, and installed 20.10, with a side-track into 21.04.

Thank you,

Dominic L. Hilsbos, MBA 
Vice President – Information Technology 
Perform Air International Inc.
DHilsbos at PerformAir.com 
www.PerformAir.com


-----Original Message-----
From: Sean Mooney [mailto:smooney at redhat.com] 
Sent: Wednesday, July 28, 2021 9:32 AM
To: Dominic Hilsbos; openstack-discuss at lists.openstack.org
Subject: Re: [nova] Early migrate error - pain point?

On Wed, 2021-07-28 at 15:49 +0000, DHilsbos at performair.com wrote:
> All;
> 
> Yesterday I ran into an issue where a live migration errored before starting the migration itself (libvirt version incompatibility).
in general that shoudl not result in the vm entering error.
the migration should enter error but the vm should remain in active state provided this failed in prelive migration.

what release did this happen in.

we shoudl raise a   DestinationHypervisorTooOld excption
https://github.com/openstack/nova/blob/master/nova/exception.py#L557-L559
if the target hypervior is too old
https://github.com/openstack/nova/blob/97e1a6bece29e383f55bb969c69983153df9ffc7/nova/conductor/tasks/live_migrate.py#L340-L353

  if source_version > destination_version:
            raise exception.DestinationHypervisorTooOld()


that check was added 8 years ago 
https://github.com/openstack/nova/commit/2d7beddc0bb7830c2a8bf893b9221c0de568c55d

if you are seeing this today i would file a bug for it with the full traceback and opentack versions and hypervior verions

> 
> This left the instance in an error state, even though it continued to run normally on the original host.
> 
> Has anyone else run into this?  Could this be a candidate for the current pain point hunt?
it has happened in the past due to bugs but im not aware of this happening any more on master.
im not sure if this shoudl be added into the pain point since if its happing it just a normal bug but it proably does not hurt either.
nova however should already be handeling it.


failures in prelive migration should always leave teh vm in the active sttate.
failure in post livemigration should generall leave the vm in the error since we cant rollback.
failure migrate when we call libvirt sometime are recoverable and sometimes not so it will depend.


> 
> Thank you,
> 
> Dominic L. Hilsbos, MBA 
> Vice President - Information Technology 
> Perform Air International Inc.
> DHilsbos at PerformAir.com 
> www.PerformAir.com
> 
>