[moVirt] Expanding oVirt

I am planning a basic 3-host hyperconverged oVirt cluster and am very happy with tests I have conducted regarding the deployment. I have a question regarding expanding the cluster and cant seem to find a direct answer. My hosts have a limited number of HDD slots and am curious about expanding the gluster volumes. Is this a simple process of adding another host or hosts as I go and adding the gluster bricks to the volume and rebalancing? I also recall seeing a hard limit of nine hosts in a cluster. Is this correct? Thank you,