Tip: SQL Server Single user mode in Windows 2008 Cluster

At first I thought starting SQL Server in Single user mode is easy in Windows 2008 fail-over cluster. But I was wrong, If I just add ‘;-m’ in start-up parameter and starts it, the SQL server will start in single user mode via cluster. But we wont be able to log in. The cluster service logs in before us. And so we might see an error like below.

Login failed for user ‘Domain\user’. Reason: Server is in single user mode. Only one administrator can connect at this time. [CLIENT: xx.xx.xx.xx]

Now what do we do? Below is how I overcame this problem.


  1. Take the SQL Server cluster group offline.
  2. Now just make the Disk and the cluster virtual name alone online for the SQl Server Cluster group.
  3. start command prompt with admin rights and type below command.
    • net start “SQL Server (instancename)” /m
  4. Open a command prompt with “Run as Administrator” option and now you can login to SQL Server via sqlcmd with any account that has access to SQL Server or an account that has admin rights on the Operating System.

Hope this helped !

Author: Sherbaz

Being a gadget enthusiast, He always felt good to try new programming languages and techniques. But never goes in-depth anywhere. www.SplitExpense.in was found when he tried php, html, javascript and mysql. Being an electronics engineer, he is also interested to build small gadgets and tools in embedded and digital electronics. As a profession, he handles microsoft sql server database and calls himself a database administrator

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