How to Fix: Move MS SQL Databases to Another Drive, Partition

Dennis Faas's picture

Infopackets Reader Philip S. writes:

" Dear Dennis,

We are running Windows 10 on our office machine which has Microsoft SQL (MS SQL) installed. On that machine we use Microsoft SQL Server Manager to enter in data into our databases, though other machines can access the Microsoft SQL databases through the network using MS Access DSN files. A few years ago we hired someone to set up our databases; however, we are now running out of space on the C drive as the databases have grown significantly in size. We would like to move the MS SQL databases and then set up a RAID to make the data redundant. We currently do not have any backups of the databases. It is my understanding that you cannot simply copy the database files to another disk due to permissions issues and the fact that the databases are live. We are in way over our head and need your help moving the SQL databases to another drive. Can you please help? "

My response:

I asked Philip if he would like me to connect to his server using my remote desktop support service in order to have a closer look, and he agreed.

Below I will discuss my findings.

How to Fix: Move MS SQL Databases to Another Drive, Partition

I have a lot of experience with mySQL databases on Linux and moving those databases are relatively simple - you just shut down the mySQL service, move the data, then edit a config file and/or make a symbolic link to another path and everything works. But that is not the case when it comes to moving MS SQL databases.

By default, when a user installs Microsoft SQL Server to the system, it is installed onto the C Drive. From there, four system databases are created: master, model, msdb, and temp.

The master database contains all of the system level information for SQL Server, including logins, linked servers, endpoints, and other things. The model database is used as a template whenever a new user database is created. The MSDB database is used by the SQL Server Agent, database mail, Service Broker, and other services. The temp database is one of the most important databases and is used for sorting data, snapshots, and other important system activities.

All these databases are required for Microsoft SQL Server to function properly. By default, all other user created databases are installed to the same location (typically C:\Program Files\Microsoft SQL Server\MSSQL14.SQLEXPRESS\MSSQL\DATA, etc).

Now that's said, let's move on.

Ideally when you move the user databases, the system databases should be moved to the same location. The reasoning here is that the system databases are just as important as the user databases. If you are going to make data redundant using a RAID, all databases should be on the same partition.

How to Move MS SQL Databases to Another Drive, Partition

Before we begin, a word of warning -

Moving databases can be extremely nerve wracking. If anything fails along the way you could be dealing with very serious issues that will prevent MS SQL from starting up or your databases to go missing (and the data along with it), or having data pointing to different drive locations.

I suggest you ONLY attempt to do the move if you are confident in your abilities, and can troubleshoot anything that comes your way in case of an error. I also VERY HIGHLY recommend you test the move using a virtual machine (of the server) before applying it to a live machine. That way you can get a feel for any errors that might come your way BEFORE making the changes permanent on the live system. Lastly, do not attempt to move databases during work hours. You will need to do this during a time when it will note interrupt anyone or any programs that use the databases.

If in doubt, hire a professional - such as myself - to manage the move for you. I can connect to your system remotely manage everything. You can contact me using the contact form online the site.

With that said, you can move the databases using the following approach. Note that I have generalized things because each system is different:

  1. First, export / backup all system and user databases before proceeding. I also suggest making a disk image backup of the system in case your backups somehow fail.


    BACKUP DATABASE [test-db] TO DISK = 'd:\backups\test-db.bak' WITH INIT, COPY_ONLY;
  2. Next, kill all connections to the databases.

    /* kill all sessions to database to prepare backups */

    USE [master];
    DECLARE @kill varchar(8000) = '';
    SELECT @kill = @kill + 'kill ' + CONVERT(varchar(5), session_id) + ';'
    FROM sys.dm_exec_sessions
    WHERE database_id = db_id('MyDB')

  3. Stop the MS SQL service.

  4. Use Robocopy to copy the master, model, and msdb databases to a new location (example: d:\data)


    robocopy "C:\Program Files\Microsoft SQL Server\MSSQL13.SQLEXPRESS\MSSQL\DATA" d:\db msdbdata.mdf /E /ZB /DCOPY:T /COPYALL /R:1 /W:1 /V /TEE
  5. Launch the SQLServerManager.msc snap-in; select SQL Server Services on the left, then "SQL Server (SQLEXPRESS)" on the right. Right click and select Properties, then go to the "Startup Parameters" tab. Here you need to change (-L, -D, -E) parameters to point to the new Data folder path.


    mmc.exe /32 C:\WINDOWS\SysWOW64\SQLServerManager13.msc

    -dC:\Program Files\Microsoft SQL Server\MSSQL1x.SQLEXPRESS\MSSQL\DATA\master.mdf -> -dd:\db\master.mdf
    -eC:\Program Files\Microsoft SQL Server\MSSQL1x.SQLEXPRESS\MSSQL\Log\ERRORLOG -> -ed:\db\ERRORLOG
    -lC:\Program Files\Microsoft SQL Server\MSSQL1x.SQLEXPRESS\MSSQL\DATA\mastlog.ldf -> -ld:\db\mastlog.ldf
  6. Once that is done, restart MS SQL Service, login to shell, and show all databases to ensure your paths are correct.

    /* show all paths for database files */

    SELECT AS DBName, type_desc AS FileType, Physical_Name AS Location FROM sys.master_files mf INNER JOIN sys.databases db ON db.database_id = mf.database_id

  7. Use the backup and restore method to move your user databases. BE VERY CAREFUL and pay attention to any error messages along the way. Use the ROLLBACK IMMEDIATE command to prep the database before the move.


    USE [master];

    RESTORE DATABASE [test-db] FROM DISK = 'd:\backups\test-db_20190103.bak'
    Move 'test-db' To 'd:\db\test-db.mdf',
    Move 'test-db_log' To 'd:\db\test-db_log.ldf';
  8. Show all database paths to ensure the move is successful.

    /* show all paths for database files */

    SELECT AS DBName, type_desc AS FileType, Physical_Name AS Location FROM sys.master_files mf INNER JOIN sys.databases db ON db.database_id = mf.database_id


I hope that helps.

Once again, this is a general approach so you will need to look at specifics for your case, such as the name of the database as well as the .MDF file locations when exporting the data (I.E. backing it up).

Additional 1-on-1 Support: From Dennis

If all of this is over your head, or if you need help moving your MS SQL databases to another drive or partition, I can help using my remote support service. Simply contact me, briefly describing the issue and I will get back to you as soon as possible.

Got a Computer Question or Problem? Ask Dennis!

I need more computer questions. If you have a computer question - or even a computer problem that needs fixing - please email me with your question so that I can write more articles like this one. I can't promise I'll respond to all the messages I receive (depending on the volume), but I'll do my best.

About the author: Dennis Faas is the owner and operator of With over 30 years of computing experience, Dennis' areas of expertise are a broad range and include PC hardware, Microsoft Windows, Linux, network administration, and virtualization. Dennis holds a Bachelors degree in Computer Science (1999) and has authored 6 books on the topics of MS Windows and PC Security. If you like the advice you received on this page, please up-vote / Like this page and share it with friends. For technical support inquiries, Dennis can be reached via Live chat online this site using the Zopim Chat service (currently located at the bottom left of the screen); optionally, you can contact Dennis through the website contact form.

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LouisianaJoe's picture

You are making it much too complicated. There is a simple solution. Backup the database to a file. Create a new database on the other media. Then restore the backup to the new database.

For restore database select device as source. Click on the box that contains "..." then click Add and select backup file.

Click Options and click "Overwrite the existing database (WITH REPLACE)"

Then select files and override the file locations to the new database files.

Click OK and and you will restore the backup to the new database.

Right click the old database and rename it.

Right click the new database and rename it to the name of the original database.

I have used this method to use copies of my customer's databases for testing.

I have been using SQL Server for over 20 years and I have been developing database applications since VB 6 and Powerbuilder.

I have been programming for 52 years.

Dennis Faas's picture

Your method uses the GUI and mine uses the command line. They are near identical methods, just done differently. To say my method is complex is a matter of opinion. Since your method uses the GUI you need to be extremely specific as to where to point and click in the interface to get the job done, and that may change with different revisions of MS SQL Server Manager. Mine uses the command line so the instructions should always be the same. It is a matter of cutting and pasting the instruction into a command line. That seems a lot easier to me, especially if you are instructing others to do the same.

Lastly, your method does not take into account modifying the master, model, msdb locations which requires editing the Startup Parameters, and moving those files with permissions required. There is no way to issue a restore move on a backup for the master, model and msdbs as far as I recall since they are in use by the system, hence service needs to be shut down, Robocopy used, then parameters changed.

LouisianaJoe's picture

I agree with you about moving the master. I have never had to move it as it is small enough to remain where it is. I have always used the GUI and it has worked for me. I have also found that it is easier to teach a user to use the GUI. One of my customers started out as a data entry clerk. She is now a systems analyst because of my teaching her to do the job. She would not have a clue using the command lines.

I enjoy reading your articles and I usually learn something new.