Uhhhh...I think you need to slap your friend.
/dev/null is a black hole. A bottomless pit in which you can throw anything and it disappears forever. It's generally used as a destination where you can pipe script output that you don't want. It can't be used for backing anything up, as anything that's sent to /dev/null is gone.
Your friend probably told you that as a joke, assuming you wouldn't actually take him seriously. Similar to the old chat room/online gaming joke to hit Alt+F4 to increase your bandwidth.
Last edited by suicidaleggroll; 10-13-2012 at 03:11 PM.