Quick Tip – Fixing A Locked LoadRunner Results Directory

Posted on March 9th 2011 by Joel Deutscher

Everynow and then, Vugen will have a little episode and decide that its default results directory is locked, and you will be presented with an friendly dialog box like the one below.

The result directory is locked

If you have ever wondered what is going on, it turns out the culprit is mmdrv.exe. This executable is the Multithreaded Driver Command Line application that is used to simulate virtual users, and killing all instances from the task manager will remove any locks on your results directory, and you can go back to normal vugenning.

While most of us don’t mind using multiple directories, it seems that even in Vugen 11, the replay log window will always show the log of the first results directory after playback. This can be very confusing when debugging scripts.

This exe can also be used manually to execute vuser scripts from the command line. This can be handy for environment smoke tests. I will write more about some alternate uses for mmdrv.exe in a later post.

About the Author

Joel Deutscher is an experienced performance test consultant, passionate about continuous improvement. Joel works with Planit's Technical Testing Services as a Principal Consultant in Sydney, Australia. You can read more about Joel on LinkedIn.


  1. venkata says:

    This is very good.. intersting.

  2. Ervin Onley says:

    Thanks for your article! I have always wondered why that happens.