Create large empty files for testing

To create  files for quota limit/uploading and testing purposes, open the Terminal – use Spotlight on Mac OS or – Applications > Utilities –  type the following command and press Enter:

mkfile -n 19m ~/Desktop/LargeTestFile

This will create a file named “LargeTestFile” on your Desktop with 19 MB. Change the number of the parameter “-n” to create files with different sizes.

Right-click the file on your Desktop and click on “Get Info” to check the size of file or type

du -h filename

to display the size on the Terminal.

mkfile(8) Mac OS X Manual Page