I was looking forward to that presentation for exactly that reason: But it completely bypassed the HCI scenario, was very light on details and of course assumed that everything would just work, because there is no easy fail-back and you're probably better off taking down the complete farm during the upgrade. If you are actually depending on that farm to operate,... In the mean-time I try to make sure I have a plan-B and C solution in case the official procedure fails, but have *.ova (plan-C) imports fail (again) in extract_ova.py on the single-node 4.4.2 HCI cluster that I have set up as target to do migration testing... a bug far to familiar for a newest release. I'll be testing re-attachable NFS domains next (plan-B), but for me *.ova exports and imports are still the most fundmental operations any hypervisor needs to support: If OVA is the wrong file format, fine, just do another one. But IMHO turning a machine into a file and a file into a machine is the very definition of what hypervisors do. And a release that doesn't seem to test this operation, does not rhyme with "solution for your entire enterprise" on the oVirt home page.