This is how to set it up:
goto Control Panel » Primary Settings
Select the logging tab.
Log MySQL Errors? Enable this
MySQL Error Log Storage Directory: enter a path if it is missing to a valid location. It will be like the Absolute PATH to Main Directory: from the Control Panel » DB, Paths & URLs
Then click on the click to test directory link.
If all is set you will get Test passed. Also it will write a file called like testfile.
