A. Exchange 2010 is supported on the 64-bit editions of both Server 2008 and Server 2008 R2, but you can't mix the OSs within a single DAG. This limitation is because DAGs use Windows failover clustering behind the scenes, and failover clustering doesn't support a mix of Server 2008 and Server 2008 R2 nodes in the same cluster (because of differences in cluster implementation).
If you want a mix of Server 2008 and Server 2008 R2, you'll need to have multiple DAGs, each containing one version of Windows.
- Q. Are Database Availability Groups (DAGs) included in the standard edition of Exchange Server 2010?
- Exchange 2010: The Migration Story
- Q. I'm trying to connect to my Exchange 2010 server using POP3, but it's failing. What's wrong?
- Q. I read that I only need the standard edition of Windows Server 2008 for Exchange Server 2010. Is this right?
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