Have you ever been in a situation when your system is freezed/terribly slow aka "what the hell is going on?" moment. This is probably the most frequent annoying thing that happens on computer. Whenever I face something like this I used to run top to catch the culprit but sometimes this is not the result of over occupied processor but because of constant hard disk access which are not visible with top most of the times. Well linuxers, now we have a solution to this problem, Iotop, a python coded brother of top.