Update Rollup 1 (UR1) for Exchange Server 2010 is available for public download,  and we recommend installing it on all of your Exchange 2010 servers.  In a few days, we'll refresh our content on TechNet, and the refresh will include step-by-step instructions for installing UR1 on Mailbox servers that are members of a database availability group (DAG).  In the meantime, I thought I would post the steps here so you don't have to wait for the content refresh.  So, here they are:

Servers that are members of DAGs do not use Microsoft Update to install update rollups. Instead, update rollups must be downloaded from the Microsoft Download Center and installed manually. When you install an update rollup on a server that is a member of a DAG, several services will be stopped during the installation, including all Exchange services, and the Windows Cluster service. The general process for installing update rollups on a DAG member is as follows:

  • Suspend activation for the databases on the server being updated.
  • Perform a server switchover so that all databases on the server are passive copies. There will be a brief interruption in service for the mailboxes hosted on the active databases during the switchover process.
  • Install the update rollup.
  • Resume activation for the databases on the updated server.
  • Perform database switchovers as needed.

You can download the latest update rollup for Exchange 2010 from the Microsoft Download Center.

To update all DAG members, perform the following procedures on each member of the DAG, one at a time.  You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Database availability groups" entry in the High Availability Permissions topic.

Install a Update Rollup on a Database Availability Group Member

Suspend activation for the database copies on the server being updated

  1. Run the following command in the Exchange Management Shell:

Get-MailboxDatabaseCopyStatus -Server <Server> | Suspend-MailboxDatabaseCopy -ActivationOnly -Confirm:$False -SuspendComment "Install update rollup for Exchange 2010"

Perform a server switchover on the server being updated

  1. In the console tree, navigate to Server Configuration > Mailbox.
  2. In the result pane, select the Mailbox server you want.
  3. In the Actions pane, select Switchover Server.
  4. In the Switchover server database copies dialog box, do one of the following:
  • Accept the default setting of Automatically choose a target server (in which case, the system automatically selects the best Mailbox server for each database being switched over), and then click OK.
  • Use the specified server as the target for switchover, click Browse to select a Mailbox server, and then click OK.

Install the update rollup

  1. Close all Exchange management tools.
  2. Right-click the update rollup file (.MSP file) you downloaded and 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.

Resume activation for the databases on the updated server

  1. Run the following command in the Exchange Management Shell:

Get-MailboxDatabaseCopyStatus -Server <Server> | Resume-MailboxDatabaseCopy

Perform database switchovers as needed

  1. In the console tree, navigate to Organization Configuration > Mailbox.
  2. In the result pane, click the Database Management tab, and then right-click the mailbox database whose copy you want to activate.
  3. In the action pane, click Activate a Database Copy.
  4. On the Activate a Database Copy page, click Browse to select the server you updated.
  5. Select the desired setting for the automatic database mount dial setting on the selected server.
  6. Click Move to activate the selected passive copy of the database to the updated server.
  7. On the Completion page, review the following, and then click Finish to close the wizard.