Installing update rollups on DAG members is a straight forward task. We have to make sure that all the active databases have been moved to a different DAG member, activation of all databases on the server to be patched is blocked, mailbox database copy is suspended etc.
Basically, the procedure is straightforward and should be followed per DAG member:
1.Appoint (next) DAG member;
2.Move away all active copies on that DAG member;
3.Prevent copies from activating on that DAG member;
4.Perform maintenance, e.g. down or upgrade DAG member;
5.Enable possible activation on that DAG member again;
6.Optionally redistribute database copies.
Microsoft has two new scripts in the ?C:Program FilesMicrosoftExchange Serverv14Scripts? folder of Exchange 2010 SP1. StartDAGServerMaintenance.ps1 and StopDAGServerMaintenance.ps1.
In order to install a rollup on 2010 SP1 , follow the steps below.
1.Use the StartDagServerMaintenance.ps1 script to put the DAG member in maintenance mode
2.Install the update rollup
3.Use the StopDagServerMaintenance.ps1 script to take the DAG member out of maintenance mode and put it back into production
4.Use the RedistributeActiveDatabases.ps1 script to re-balance the active database copies across the DAG