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Starting SQL Server in Single-User Mode

Under certain circumstances, you may have to start an instance of Microsoft SQL Server in single-user mode by using the startup option -m. For example, you may want to change server configuration options or recover a damaged master database or other system database. Both actions require starting an instance of SQL Server in single-user mode.

When you start an instance of SQL Server in single-user mode, note the following:

  • Only one user can connect to the server.
  • The CHECKPOINT process is not executed. By default, it is executed automatically at startup.

Note

Stop the SQL Server Agent service before connecting to an instance of SQL Server in single-user mode; otherwise, the SQL Server Agent service uses the connection, thereby blocking it.

See Also

Tasks

How to: Start an Instance of SQL Server (sqlservr.exe)

Concepts

Using a Dedicated Administrator Connection
allow updates Option
Using the SQL Server Service Startup Options

Other Resources

sqlcmd Utility
CHECKPOINT (Transact-SQL)
sp_configure (Transact-SQL)

Help and Information

Getting SQL Server 2005 Assistance