Hi all , I need to setup DAG on exchange 2010. Do i need an enterprise edition of exchange 2010? RegardsMCITP Enterprise Messaging Administrator, MCITP Enterprise Administrator, MCSE, MCDBA

No. You need Enterprise edition of Windows, but you can use a DAG with standard of Exchange 2010, as the system requirements pages on Technet state. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources

Dear Simon, Can you provide with the link of this page? MCITP Enterprise Messaging Administrator, MCITP Enterprise Administrator, MCSE, MCDBA

From (Software Requirements section): http://technet.microsoft.com/en-us/library/dd638104.aspx "DAGs are available in both Exchange 2010 Standard Edition and Exchange 2010 Enterprise Edition. In addition, a DAG can contain a mix of servers running Exchange 2010 Standard Edition and Exchange 2010 Enterprise Edition. Each member of the DAG must also be running the same operating system. Exchange 2010 is supported on both the Windows Server 2008 and Windows Server 2008 R2 operating systems. All members of a DAG must run either Windows Server 2008 or Windows Server 2008 R2. They can't contain a combination of both Windows Server 2008 and Windows Server 2008 R2. In addition to meeting the prerequisites for installing Exchange 2010, there are operating system requirements that must be met. DAGs use Windows Failover Clustering technology, and as a result, they require the Enterprise version of Windows." Tim Harrington | MVP: Exchange | MCITP: EMA 2007/2010, MCITP: Server 2008, MCTS: OCS | Blog: http://HowDoUC.blogspot.com | Twitter: @twharrington

Hi Elie, Simon and Tim are right. Here is a post about DAG requirements, hope it helps DAG requirements http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/4a376882-d105-4b3b-b6de-e4f9f323eea6 Thanks, Evan 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.

Hello Elie. http://technet.microsoft.com/en-us/library/dd979799%28EXCHG.140%29.aspx via this link we can understand that only window server 2008 enterprice edition is supported. that's because of failover clustering feature which is built in enterPrice Edition. Underneath every DAG is a Windows failover cluster. Failover clusters use the concept of quorum. Quorum isn't a new concept for Exchange 2010. Highly available Mailbox servers in previous versions of Exchange also use failover clustering and its concept of quorum. Quorum is important to ensure consistency, to act as a tie-breaker to avoid partitioning, and to ensure cluster responsiveness. thanks in advance :)

http://technet.microsoft.com/en-us/library/dd979799%28EXCHG.140%29.aspx vai this link we can understand that only window server 2008 enterprice edition is supported. that's because of failover clustering feature which is built in enterPrice Edition. Underneath every DAG is a Windows failover cluster. Failover clusters use the concept of quorum. Quorum isn't a new concept for Exchange 2010. Highly available Mailbox servers in previous versions of Exchange also use failover clustering and its concept of quorum. Quorum is important to ensure consistency, to act as a tie-breaker to avoid partitioning, and to ensure cluster responsiveness: