Environment setup:
3 Host HCI GlusterFS setup. Identical hosts, Dell R720s w/ Intel E5-2690 CPUs
1 default data center (4.2 compat) 1 default cluster (4.2 compat)
Situation: I recently upgraded my three node HCI cluster from Ovirt 4.2 to 4.3. I did so by first updating the engine to 4.3 then upgrading each ovirt-node host to 4.3 and rebooting.
Currently engine and all hosts are running 4.3 and all is working fine.
To complete the upgrade I need to update cluster compatibility to 4.3 and then data centre to 4.3. This is where I am stuck.
The CPU type on cluster is "Intel SandyBridge IBRS Family". This option is no longer available if I select 4.3 compatibility. Any other option chosen such as SandyBridge IBRS SSBD will not allow me to switch to 4.3 as all hosts must be in maintenance mode (which is not possible w/ self hosted engine).
I saw another post about this where someone else followed steps to create a second cluster on 4.3 with new CPU type then move one host to it, start engine on it then perform other steps to eventually get to 4.3 compatibility.
I have the exact same hardware configuration and was able to change to "SandyBridge IBRS SSBD" without creating a new cluster. How I made that happen, I'm not so sure, but the cluster may have been in "Global Maintenance" mode when I changed it.