right now I have updated an infra from 4.1.1 to 4.1.5.

OS is CentOS 7.3 on the 2 hypervisors and on the engine (a separate server) and has remained that, because CentOS 7.4 not yet released, but coming soon.

Questions. When 7.4 released, will ot be some testing from oVirt guys to confirm that I can:

- update OS of engine and hypervisors to 7.4 without any problem?

- update another cluster still in 4.1.3 and CentOS 7.3 to 4.1.5 and 7.4 in one step?

or any guideline?

- suppose I have RH EL with oVirt does the same apply?

Already tested?

This last one below is more a question for support, but in case suggestions are useful in advance: 

I searched similar information for RHEV but it seems I was not able to find, because RHEV 4.1 has been released before RH EL 7.4:

If I should start an evaluation of RHEV 4.1 and I decide to stay with plain RHEL server and not RHV-H, should I force with rhsm to stay on 7.3 and install latest 4.1 packages or can I directly start with 7.4 OS?

Is it true that there is a plan to not support plain RH EL hosts in the future, but only RHV-H hosts or not?

Thanks in advance,

Gianluca