Has anyone encountered issues with a 2-DAG member setup for Exchange 2010 SP1 when the Operating Systems differ where DAG 1 is on Server 2008 and DAG 2 is on Server 2008R2. Thanks.

That isn't a supported configuration. Both sides of the DAG need to be the same OS. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Agree with Andy, OS got to be the same if you want to deploy DAG... Cheers,Gulab | MCTS-MCITP Messaging: 2010 | MCTS-MCITP Messaging: 2007 | MCC 2011 | Skype: Gulab.Mallah

It is right. All DAG member must with same OS. DAG server require the Windows Failover Clustering (WFC) server feature, which is only available in the Enterprise Windows or Datacenter Edition of Windows 2008 and Windows 2008 R2.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.