Restore a Microsoft SQL Server Master Database

Summary

Restoring the Microsoft SQL Server master database running on a DxEnterprise cluster.

Information

This is very much the same as how you would do so with a stand-alone instance. There are really just two additional steps you need to take to successfully restore a master database:

1. Freeze the Vhost before restoring master.

2. Unfreeze the Vhost after restoring master.

The following is a general procedure that you can use to restore the master database:

1. Remote Desktop into the active node that is currently hosting the instance.

2. Connect DxAdmin.

3. Right-click on the Vhost and select Freeze virtual host on node.

4. Start the instance in single-user startup mode so that master can be restored.

   • Windows - Open Regedit and browse to the instance key HKLM\Software\Microsoft\Microsoft SQL Server\MSSQLServer\Parameters and add SQLArg3 with string value of “-m”. Restart the instance service for the changes to take effect.

   • Linux - Launch mssql-server with the -m parameter /opt/mssql/bin/sqlservr -m.

5. Restore master database. See How to: Restore the master Database (Transact-SQL) for additional information.

6. Once master is restored, use Regedit (Windows only) to remove the single-user startup parameter. Restart the instance service for the changes to take effect.

7. In DxAdmin, right-click on the Vhost and select Unfreeze virtual host to put the Vhost back into normal operation again.