Hello There, If we try to host Active and Passive Database Copies on the Same Server with Exchange 2010 SP1, can we install the Exchange on Windows Windows 2008 Standard edition SP2 instead of Windows 2008 Enterprise edition SP2? Thanks.

No - to create a DAG, you need to run Enterprise Windows. There would be little point in having a single-node DAG with multiple DB copies, but that isn't supported anyway.

Thank you for quick reply. That's what I thought too. BTW, can we install DAG on one Exchange 2010 SP1 server environment to host Active and Passive Database Copies on the Same Server ? http://technet.microsoft.com/en-us/library/ee712771.aspx

Thank you for quick reply. That's what I thought too. BTW, can we install DAG on one Exchange 2010 SP1 server environment to host Active and Passive Database Copies on the Same Server ? http://technet.microsoft.com/en-us/library/ee712771.aspx You cannot have active and passive copies of the same database on the same server. But you can have active and passive copies of different databases on the same server. http://technet.microsoft.com/en-us/library/dd979802.aspx "Database copies can be created only on Mailbox servers that don't host the active (mounted and in-use) copy of a database. You can't create two copies of the same database on the same server."Tim Harrington | MVP: Exchange | MCITP: EMA 2007/2010, MCITP: Lync 2010, MCITP: Server 2008, MCTS: OCS | Blog: http://HowDoUC.blogspot.com | Twitter: @twharrington

In a DAG scenario, you have multiple copies of each database. For a given database, each copy has a specific "activation order". We tend to think of activation order 1 as the actiove copy, activation order 2 as the first passive copy, etc. If I have four databases, DB1-DB4, and each database has 2 copies, activation order 1-2, then I CAN do something like this: Server1 Database1, activation 1 Database2, activation 2 Database3, activation 1 Database4, activation 2 Server2 Database1, activation 2 Database2, activation 1 Database3, activation 2 Database4, activation 1. I CANNOT, on the other hand, do something like: Server 1 Database1, activation 1 Database1, activation 2 ... For any given database, only one copy may reside on a given server. John

understand this. It seems Microsoft has removed LCR from Exchange 2010. What will be alternative solution for one server environment for mailbox database quick recovery?

understand this. It seems Microsoft has removed LCR from Exchange 2010. What will be alternative solution for one server environment for mailbox database quick recovery? Dial-Tone , Database Portability , Recovery Databases and /m:RecoverServer . Those are your only real built-in options for single-server recovery. "Quick" is a relative term. If you are looking for HA, then you need to use the DAG option if you want to use native Exchange replication.

Hi, “No - to create a DAG, you need to run Enterprise Windows.” One addition, 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