Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Topic Last Modified: 2013-01-09

When you add a server to a database availability group (DAG), it works with the other servers in the DAG to provide automatic, database-level recovery from database, server, or network failures. When you remove a server from a DAG, it is no longer automatically protected from failures.

DAGs use Windows Failover Clustering (WFC) technologies. Each Mailbox server that is a member of a DAG is also a node in the underlying cluster that is used by the DAG. As a result, at any given time, a Mailbox server can be a member of only one DAG.

Looking for other management tasks related to DAGs? Check out Managing Database Availability Groups.

Prerequisites

  • A DAG has been created. For detailed steps, see Create a Database Availability Group.

  • Because DAGs use WFC technology, all servers added to a DAG must be running either Windows Server 2008 Service Pack 2 (SP2) Enterprise Edition or Windows Server 2008 R2 Enterprise Edition.

  • All servers in a DAG must be running the same operating system. You can't have DAG members that are running Windows Server 2008 SP2 and others that are running Windows Server 2008 R2.

  • If you're adding Mailbox servers running Windows Server 2012, you must pre-stage the cluster name object (CNO) for the DAG. For detailed steps, see Pre-stage the Cluster Name Object for a Database Availability Group.

  • You must remove all replicated database copies from the server before you can remove it from a DAG.

What Do You Want to Do?

Use the EMC to manage database availability group membership

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.

  1. In the console tree, navigate to Organization Configuration > Mailbox.

  2. In the result pane, click the Database Availability Group tab, right-click the DAG you want to manage, and then click Manage Database Availability Group Membership.

  3. On the Manage Database Availability Group Membership page, you can perform the following tasks.

    • To add a local server to the DAG, click Add and then use the Select Mailbox Server dialog box to select the server you want.

    • To remove a local server from the DAG, select a server from the list of members, and the click Remove icon.

  4. Click Manage to perform the configured management action (adding or removing a server).

  5. On the Completion page, review the following, and then click Finish to close the wizard:

    • A status of Completed indicates that the wizard completed the task successfully.

    • A status of Failed indicates that the task wasn't completed. If the task fails, review the summary for an explanation, and then click Back to make any configuration changes.

Use the Shell to manage database availability group membership

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.

This example adds a Mailbox server named MBX1 to a DAG named DAG1.

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Add-DatabaseAvailabilityGroupServer -Identity DAG1 -MailboxServer MBX1

This example removes a Mailbox server named MBX1 from a DAG named DAG1. Before running this command, make sure that no replicated databases exist on the Mailbox server.

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Remove-DatabaseAvailabilityGroupServer -Identity DAG1 -MailboxServer MBX1

This example removes the configuration settings for Mailbox server named MBX4 from a DAG named DAG2. MBX4 is expected to be offline for an extended period, so its configuration is being removed from the DAG while it is offline in order to establish quorum with the remaining online DAG members.

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Remove-DatabaseAvailabilityGroupServer -Identity DAG2 -MailboxServer MBX4 -ConfigurationOnly

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