[ovirt-users] Re: 4.4 -> 4.3

Export domain should work, with the usual constraints that you have to detach/attach the whole domain and you'd probably want to test with one or a few pilot VMs first. There could be issues with 'base' templates etc. for VMs that where created as new on 4.4: be sure to try every machine type first. Ideally you have 4.4 and 4.3 farms side by side, instead of rebasing your hosts on 4.3 and *then* finding issues. Things to watch out for are hardware base lines (those mitigation-enhanced CPU types can be nasty), BIOS types (Q35 vs. all others) etc. Personally I see OVA files as something that should be least risky and minimal functionality that just ought to always work. The oVirt team doesn't seem to share my opinion and views OVA as a VMware->oVirt migration tool, mostly. I still try to use OVA export/import for critical VMs, because sometimes it means I can at least resurrect them on a stand-alone KVM host (even VMware should work in theory: in practice I've seen both VMware and VirtualBox barf at oVirt generated OVA exports). Note that there is an issue with OVA exports from oVirt 4.3: They can result in empty disks due to a race condition that wasn't fixed even with the last 4.3 release. In your case, that shouldn't bite you, as you are moving in the other direction. But should you decide to go forward again be sure to check your 4.3 OVA exports via 'du -h <OVA-file>' showing more than a few KB of actuall alloaction vs. the potentially multi-TB 'sparse' disk full of zeros 'ls -l' might hint at. With oVirt I consider blind faith as extremely ill advised. Everything you haven't tested several times after every change of every component yourself, is much more likely to fail than you ever thought befit a product that carries "a free open-source virtualization solution for your entire enterprise" on its home page.