On 7/25/2019 7:50 AM, Budai Laszlo wrote:
Can you please clarify one more thing: how is the resize involved in this cold migration. Apparently it is trying to resize before it would copy the files. Is there any document that describes the steps of the migration?
Resize and cold migration are the same flow under the covers, the only difference being a resize has a new flavor while a cold migration does not (and for the libvirt driver you can't cold migrate to the same host like a resize).
I don't think we have a reference doc on the low-level resize / cold migration flow like we have for live migration [1] (we should add one though, I could probably sketch it out pretty quickly if someone can throw it into the docs). I did find this pretty old blog [2] that might help - note it's from 2014 though so parts of it might be inaccurate by now.
[1] https://docs.openstack.org/nova/latest/reference/live-migration.html [2] http://bodenr.blogspot.com/2014/03/openstack-nova-vm-migration-live-and.html