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How do I mirror two SQL Server databases?
Right click on the database and select Tasks option. Click on Mirror option. Database Properties dialog box with Mirroring page will open. Click on Configure Security option to start the configuration.
What is mirrored database in SQL Server?
A mirror database is a backup copy created on another server to ensure continuous data availability and avoid downtime. According to Microsoft SQL Server TechNet, database mirroring only works with databases that are configured for the full recovery model.
What do you need to know about Database mirroring?
mirror server. In a database mirroring configuration, the server instance on which the mirror database resides. principal database. In database mirroring, a read-write database whose transaction log records are applied to a read-only copy of the database (a mirror database).
Who is the principal server in database mirroring?
In database mirroring, the partner whose database is currently the principal database. Received transaction log records that are waiting on the disk of a mirror server. The principal server and mirror server perform complementary principal and mirror roles. Optionally, the role of witness is performed by a third server instance.
How to switch database mirror roles in SQL Server?
The principal server disconnects clients from the principal database, sends the tail of the log to the mirror server, and, in preparation for switching to the mirror role, sets the mirroring state to SYNCHRONIZING. The mirror server records the log sequence number (LSN) of the last log record received from the principal as the failover LSN.
Do you have to run the same SQL Server as the mirror server?
The mirror server instance must be running the same edition of SQL Server. A database mirroring session runs with either synchronous or asynchronous operation. Under asynchronous operation, the transactions commit without waiting for the mirror server to write the log to disk, which maximizes performance.