Steps for Installing Update Rollups on DAG Members

There are steps and sequence if you trying to install the Update Rollups on the Mailbox Server which is DAG member. Below are the general and detail steps

Installing Update Rollups on DAG Members

Installing Microsoft Exchange Server 2010 update rollups on a server that is a member of a database availability group (DAG) is a relatively straightforward process. When you install an update rollup on a server that's a member of a DAG, several services are stopped during the installation, including all Exchange services and the Cluster service. The general process for applying update rollups to a DAG member is as follows:

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 rebalance the active database copies across the DAG.

Detail steps 1 to 4 as below.

STEP 1:

Run the StartDagServerMaintenance.ps1 script on the server being updated

Run the following command in the Exchange Management Shell from the Scripts directory:

.\StartDagServerMaintenance.ps1 <ServerName>

STEP 2:

Install the update rollup

1.       Close all Exchange management tools.

2.       Right-click the Exchange update rollup file (.msp file) you downloaded, and then select Apply.

3.       On the Welcome page, click Next.

4.       On the License Terms page, review the license terms, select I accept the License Terms, and then click Next.

5.       On the Completion page, click Finish.

STEP 3:

Run the StopDagServerMaintenance.ps1 script

Run the following command in the Shell from the Scripts directory:

.\StopDagServerMaintenance.ps1  <ServerName>

STEP 4:

Re-balance the DAG, as needed

Run the following command in the Shell from the Scripts directory to optionally balance the DAG by Activation Preference and to produce a report when balancing is complete:

.\ RedistributeActiveDatabases.ps1 -DagName <DAGName> -BalanceDbsByActivationPreference -ShowFinalDatabaseDistribution