OpenNebula HA Raft for 2 nodes

With corosync and pacemaker I built two HA powerfull nodes with third weak node for just a pacemaker quorum. So that made possible to migrate VMs during reboot of main nodes and to have a clear state.

Is it possible to make the same with HA Raft?
As it is dicribed, 3 nodes is the minimum in cluster.
But how to mark one of that 3 hosts not to get VMs on board, in other words to stay as a quorum?

if it’s not still invented, think about rates as it was in pacemaker for specific hosts