How to: Manually Fail Over a Database Mirroring Session (SQL Server Management Studio)
When the mirrored database is synchronized (that is, when the database is in the SYNCHRONIZED state), the database owner can initiate manual failover to the mirror server.
During a manual failover, the principal and mirror server roles are swapped for the database on which the failover occurs. The mirror database becomes the principal database and the principal database becomes the mirror. For example, the following table shows the how a manual failover swaps the roles of two mirroring partners: SQLDBENGINE0_1 and SQLDBENGINE0_2.
| Server | Before failover | After failover |
|---|---|---|
|
PRINCIPAL |
MIRROR |
|
MIRROR |
PRINCIPAL |
Note that the server roles for other database mirroring sessions are not affected. For more information, see Manual Failover.
To manually fail over database mirroring
Connect to the principal server instance and, in the Object Explorer pane, click the server name to expand the server tree.
Expand Databases, and select the database to be failed over.
Right-click the database, select Tasks, and then click Mirror. This opens the Mirroring page of the Database Properties dialog box.
Click Failover.
A confirmation box appears. If you confirm that you want to fail over to the mirror database, failover proceeds, and principal and mirror server roles are swapped. The mirror database becomes the principal database and the principal database becomes the mirror.
Important
If you have modified any properties since opening the Mirroring page, those changes will not be saved.
The dialog box closes automatically.
See Also
Tasks
How to: Pause or Resume a Database Mirroring Session (SQL Server Management Studio)
How to: Remove Database Mirroring (SQL Server Management Studio)