Connecting Clients to a Database Mirroring Session (SQL Server)
To connect to a database mirroring session, a client can use either SQL Server Native Client or .NET Framework Data Provider for SQL Server. When configured for a SQL Server 2008 database, these data access providers both fully support database mirroring. For information about programming considerations for using a mirrored database, see Using Database Mirroring. In addition, the current principal server instance must be available and the login of the client must have been created on the server instance. For more information, see Troubleshooting Orphaned Users. Client connections to a database mirroring session do not involve the witness server instance, if one exists.