My boss is wanting to implement two new DAG's on our Exchange 2010 infrastructure. He wants to setup a new Exchange Server in AMERICA and replicate South America's databases to it. He also wants to replicate Europe's databases to this same server in AMERICA. The South America and Europe Exchange servers have all three roles installed locally (HT/CAS/MB). Questions.....
1. Should the new AMERICA server have all three roles or only MB role?
2. Is it okay to have 2 multi-role Exchange servers in a DAG across WAN sites?
3. After the new DAG is created, can I add the existing databases to the DAG and then will they replicate or do I have to create new databases and migrate the mailboxes into these DB's?