Just looking for some deployment advice. We have 2 multi-role exchange servers (HUB,CAS,MB) in 2 active directory sites connected with a 100mbps VPLS tunnel. Server A is currently in production and we'd like to extend DAG to server B.
I know that in a 2 member DAG we will need a witness server. Can server A also be a witness server or is it better to have a third server perform this role?
Can the 2 exchange servers remain multi-role or should I separate HUB and CAS onto their own server in each site? This isn't a particularly large exchange environment. There's less than 100 mailboxes.
I would like to keep things as simple as possible.
Thanks for the input.