Location of Master MDF files

The following question was asked on my website:

What file does SQL Server use to find the location of the master.mdf file?

website question

Without context this could mean a few different things. Are you trying to find out where master.mdf is located, or are you trying to move it?

The answer is its not saved in a config file, it is stored in the registry editor. Now that’s that quite true since the registry data is stored somewhere in a file, but I think that it out of the context of this question.

The actual path may vary depending on the version of SQL Server, but it looks something like this:

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL15.SQL2019\MSSQLServer\Parameters

You can also get to it through the SQL Server configuration manager.

The three startup parameters shown there explained are:

• -d The path to the master database primary file.
• -e The path to the SQL Server error log file.
• -l The path to the master database transaction log.

If you were interested in just looking these up, you could do that with a TSQL query:

USE master;
GO
SELECT * 
  FROM sys.database_files;

I hope this helps answer the question.

-Steve Stedman

More from Stedman Solutions:

Steve and the team at Stedman Solutions are here for all your SQL Server needs.
Contact us today for your free 30 minute consultation..
We are ready to help!