A. If a mailbox server is part of a high availability group in Exchange 2007, the server can't host the CAS, Hub Transport, or any other role. With Exchange 2010, you can have a single server hosting CAS, the Hub Transport role, unified messaging, and a mailbox server as part of a DAG. Of course, in most scenarios you wouldn't want to co-host these roles for performance reasons, but it is now a possible combination.Related Reading:
- Q. With Microsoft Exchange Server 2010 coming, should I use single copy clusters or local continuous replication when planning my high availability for Exchange 2007?
- A First Look at Exchange 2010
- Exchange 2010: Problems, Problems, Problems
- Exchange Server 2010 Beta Tips
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