In this scenario, the DAG has had a switch over or fail over and the database is now on the wrong node. A DAG failover can cause performance issues especially in virtualized environments where one Wow, has it really been 2 months? I guess it has. For this Skunk Works project, we're attempting to fully integrate Cisco CUCM with Exchange 2010 Unified Messaging. In Part 1 we did the Cisco SIP Trunk creation & the Exchange 2010 UM Role Installation In Part 2 we actually Using Activation Policies to Prevent Database Copies Mounting in Other Sites how do I best block auto failover for each database, still being able to do a manual failover ? Reply. Paul Cunningham says. December 7, 2016 at 10:23 am Running the same CMDlets on an Exchange 2010 server shows Configure DAG in Exchange 2010. Configuring DAG (Database Availability Group) in Exchange 2010 is a straightforward process. Note following points before you start configuring DAG in Exchange 2010. A unique name for DAG is required which can be not more than 15 characters long. Microsoft Exchange Server 2010 introduced a new high availability feature called the Database Availability Group (DAG). This tutorial describes how Database Availability Groups work in Exchange Server 2010, as well as demonstrating the steps for deploying a DAG using Exchange Server 2010 SP1 and Windows Server 2008 R2. In addition, the DAG runs in DAC mode. To get Exchange 2010 up and running in the failover datacenter, I basically went through the steps described in part 12 of my "Planning, Deploying, and Testing an Exchange 2010 Site-Resilient Solution sized for a Medium Organization" articles series. In addition, if you have more than two locations in which to deploy messaging service components, Exchange 2013 also provides the ability to configure the messaging service for automatic failover in response to failures that required manual intervention in Exchange 2010. Site resilience has been operationally simplified in Excha