Linux disk usage analysis tools

Recently I found myself unable to access my workstation and confused as to why I was unable to even get past the screen locking. I quickly discovered some process was rapidly filling my hard drive to the point where it was at 100%. This, for obvious reasons, rendered my system inoperable.

Two tools I used to help discover where my disk space was going was:

du - A command line tool that helps to determine disk usage

and

Disk Usage Analyzer (baobab) - a graphical tool that provides similar information to that seen with du

The issue ended up being a problem with a 3 way file comparison that went rogue while in screen lock mode. I'm not sure why this happened but the above tools helped immensely in determining the culprit.