I wrote this up after a forum discussion in which several posters didn't really understand why ">" can free disk space when "rm" cannot.

Adding a second (or third or more!) hard drive to your computer is a great way to, well, give your computer more disk space. Ok, the concept is pretty logical but the process to make it work needs some explanation. Here’s what to do, plus one thing the Linux filesystem does brilliantly which Windows can’t do at all.