Database Availability Groups(DAGs) in Exchange 2010 is data redundancy, high availability and disaster recovery feature. Adding Multiple mailbox servers to the DAG and replicating all mailbox databases with other member servers provides automatic failover recovery at the database level. You will need just two Mailbox Server to start with the high-availability features of Exchange 2010. The database switch-over time is less than 30 seconds which will significantly improve the overall up-time. Any server in the DAG can host a copy of a mailbox database from any other server in the DAG. However, due to various reason you may have to manually failover database in Exchange 2010 DAG to another server which is holding a healthy copy of the database.
Manually Failover Database in Exchange 2010 DAG
As a usual practeice, you have the vincity of do it in two ways, using Exchange Manage Shell and Exchange Management Console. To perform a manual failover of the database using Exchange Management Console, following are the steps.
Open Exchange Management Console and Navigate to Orgonization Configuration â†’ Mailbox and click on the Database Management Tab in the right panel.
In this Scenario I will be doing a manual failover of the database DB02 from MBG-MBX01 to MBG-MBX02. To do this Right Click on the database which you wish to failover to another server, and click “Move Active Mailbox Database” as shown below.
Once you clicked on “Move Active Mailbox Database” option, you will see the “Activate a Database Copy” wizard as shown below.
Select the desired server, in my case I will be selecting MBG-MBX-02 and then select Database Mount Dial Setting. To select the Database Mount Dial Setting for the target, we will have to look into each options provided in the dropdown list as shown in the above screenshot.
|Lossless:||The Target database will not mount automatically until all generated logs in the active mailbox database is copied to passive mailbox database|
|Good Availability:||The Database will mount automatically only if the copy queue length is less then or equal to 6|
|Best Effort:||The database will be mounted irrespective of copy queue length (Caution: Data-loss may occur)|
|Best Availability:||The Database will mount automatically only if the copy queue length is less then or equal to 12|
In our Scenario, I will be selecting “Good Availability” option and click Move as shown below.
In this way you can manually failover mailbox database to different server.