currently I've a 4-nodes oVirt 4.0.4 cluster running on CentOS 7.2.

Given that we have now oVirt 4.0.6 and CentOS 7.3, what's the best update path? I was reading threads about qemu-kvm-ev 2.6 when CentOS 7.3 was released but I was wondering if with 4.0.6 release something has changed.

Moreover, I'd like to add 4 more nodes in the near future, I guess I should have all the same version and thus I must fully upgrade the original 4 nodes (both OS + oVirt) before adding new, fully up-to-date nodes, right?

Thanks!
--