WhitePaper: Using SQL Server Database Mirroring with Office SharePoint Server and Windows SharePoint Services

http://technet2.microsoft.com/Office/en-us/library/b4dfe06a-40a5-4826-8d4b-1d758a9e621a1033.mspx?mfr=true

 Introduction to Database Mirroring

Database mirroring is a new technology in Microsoft® SQL Server™ 2005 database software that can deliver high availability and high performance solutions for database redundancy. In database mirroring, transactions are sent directly from a principal database and server to a mirror database and server whenever the principal database’s transaction log buffer is written to disk. This technique can keep the mirror database nearly up to date with the principal database. You can optionally use a third server, a witness server, to enable automatic failover from the principal server to the mirror server.

Database mirroring is a primarily software solution for increasing database availability. Mirroring is implemented on a per-database basis and works only with databases that use the full recovery model. The simple and bulk-logged recovery models do not support database mirroring.

Database mirroring offers a substantial improvement in availability over the level previously possible by using SQL Server and provides an easy-to-manage alternative or supplement to failover clustering or log shipping. When a database mirroring session is synchronized, database mirroring provides a hot standby server that supports rapid failover with no loss of data from committed transactions. During a typical mirroring session, after a production server fails, client applications can recover quickly by reconnecting to the standby server.

For more information about database mirroring, see Database Mirroring in SQL Server 2005 (http://go.microsoft.com/fwlink/?LinkId=83566&clcid=0x409).

Administrators of servers running Microsoft Office SharePoint® Server 2007 or Microsoft Windows® SharePoint Services can use database mirroring and notify Office SharePoint Server or Windows SharePoint Services if the database server changes to recover quickly from database failures.