Deleting PST after migration

Hi, I'm a bit unclear about what the option delete PST after migration entails. I thought it would delete the PST file from the file system, but it could also mean to delete the PST file from the holding area or deleting the PST file from the Outlook client. After a trial migration I see the original PST is still there, with attributes set to readonly. The Holding area is empty and the PST file has disappeared from the Outlook client. So, should I delete the PST files from the filesystem manually after a succesful migration?