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

Topic Last Modified: 2012-07-23

Moving the active mailbox database is the process of designating a specific passive copy as the new active copy of a mailbox database. This process is referred to as a database switchover. A database switchover involves dismounting the current active database and mounting the database copy on the specified server as the new active mailbox database copy. The database copy that will become the active mailbox database must be healthy and current.

Looking for other management tasks related to mailbox database copies? Check out Managing Mailbox Database Copies.

What Do You Want to Do?

Use the EMC to move the active mailbox database

There are two ways you can use the EMC to move the active mailbox database. You can use the Move Active Mailbox Database wizard or you can use the Activate Database Copy option in the work pane.

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Mailbox database copies" entry in the High Availability Permissions topic.

Use the Move Active Mailbox Database wizard

  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 Move Active Mailbox Database.

  4. On the Move Active Mailbox Database page, click Browse to select the server you want to host the active copy of the database.

  5. Select the desired setting for the automatic database mount dial setting on the server that you specified in the previous step.

  6. In the Override automatic database mount dial setting on the target mailbox server list, optionally override the database mount dial settings on target master by selecting a value other than None. Possible values are:

    • Lossless   If you specify this value, the database doesn't automatically mount until all logs that were generated on the active copy have been copied to the passive copy.

    • Good Availability   If you specify this value, the database automatically mounts immediately after a failover if the copy queue length is less than or equal to 6. If the copy queue length is greater than 6, the database doesn't automatically mount. When the copy queue length is less than or equal to 6, Exchange attempts to replicate the remaining logs to the passive copy and then mounts the database.

    • Best Effort   If you specify this value, the database automatically mounts regardless of the size of the copy queue length. We recommend using caution when using this setting. Because the database will mount with any amount of log loss, using this value could result in a large amount of data loss.

    • Best Availability   If you specify this value, the database automatically mounts immediately after a failover if the copy queue length is less than or equal to 12. The copy queue length is the number of logs recognized by the passive copy that needs to be replicated. If the copy queue length is more than 12, the database doesn't automatically mount. When the copy queue length is less than or equal to 12, Exchange attempts to replicate the remaining logs to the passive copy and then mounts the database.

  7. Click Move to move the active copy of the selected database to the specified server.

  8. 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 work pane

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

  2. In the result pane, click the Database Management tab, and then click the mailbox database whose copy you want to activate

  3. In the Database Copies work pane, right-click the passive mailbox database copy that you want to activate, and then click Activate Database Copy.

  4. In Activate Database Copy, you can use the Override mount dial list to optionally override the database mount dial settings on target master by selecting a value other than None. Possible values are:

    • Lossless   If you specify this value, the database doesn't automatically mount until all logs that were generated on the active copy have been copied to the passive copy.

    • Good Availability   If you specify this value, the database automatically mounts immediately after a failover if the copy queue length is less than or equal to 6. If the copy queue length is greater than 6, the database doesn't automatically mount. When the copy queue length is less than or equal to 6, Exchange attempts to replicate the remaining logs to the passive copy and then mounts the database.

    • Best Effort   If you specify this value, the database automatically mounts regardless of the size of the copy queue length. Because the database will mount with any amount of log loss, using this value could result in a large amount of data loss.

    • Best Availability   If you specify this value, the database automatically mounts immediately after a failover if the copy queue length is less than or equal to 12. The copy queue length is the number of logs recognized by the passive copy that needs to be replicated. If the copy queue length is more than 12, the database doesn't automatically mount. When the copy queue length is less than or equal to 12, Exchange attempts to replicate the remaining logs to the passive copy and then mounts the database.

  5. Click OK to activate the passive copy. This action dismounts the current active mailbox database and makes the selected passive copy the new active mailbox database.

Use the Shell to Move the Active Mailbox Database

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Mailbox database copies" entry in the High Availability Permissions topic.

In this example, a copy of the database DB4 hosted on MBX3 is activated and mounted as the new active mailbox database. This command makes DB4 the new active mailbox database and it doesn't override the database mount dial settings on MBX3.

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Move-ActiveMailboxDatabase DB4 -ActivateOnServer MBX3 -MountDialOverride:None

This example performs a switchover of the database DB2 to the Mailbox server MBX1. When the command completes, MBX1 hosts the active copy of DB2. Because the MountDialOverride parameter is set to None, MBX1 mounts the database using its own defined database auto mount dial settings.

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Move-ActiveMailboxDatabase DB2 -ActivateOnServer MBX1 -MountDialOverride:None

This example performs a switchover of the database DB1 to the Mailbox server MBX3. When the command completes, MBX3 hosts the active copy of DB1. Because the MountDialOverride parameter is specified with a value of Good Availability, MBX3 mounts the database using a database auto mount dial setting of GoodAvailability.

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Move-ActiveMailboxDatabase DB1 -ActivateOnServer MBX3 -MountDialOverride:GoodAvailability

This example performs a switchover of the database DB3 to the Mailbox server MBX4. When the command completes, MBX4 hosts the active copy of DB3. Because the MountDialOverride parameter isn't specified, MBX4 mounts the database using a database auto mount dial setting of Lossless.

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Move-ActiveMailboxDatabase DB3 -ActivateOnServer MBX4

This example performs a server switchover for the Mailbox server MBX1. All active mailbox database copies on MBX1 will be activated on one or more other Mailbox servers with healthy copies of the active databases on MBX1.

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Move-ActiveMailboxDatabase -Server MBX1

This example performs a switchover of the database DB4 to the Mailbox server MBX5. In this example, the database copy on MBX5 has a replay queue greater than 6. As a result, the SkipLagChecks parameter must be specified to activate the database copy on MBX5.

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Move-ActiveMailboxDatabase DB4 MBX5 -SkipLagChecks

This example performs a switchover of the database DB5 to the Mailbox server MBX6. In this example, the database copy on MBX6 has a ContentIndexState of Failed. As a result, the SkipClientExperienceChecks parameter must be specified to activate the database copy on MBX6.

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Move-ActiveMailboxDatabase DB5 MBX6 -SkipClientExperienceChecks

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