I have a couple of web servers and the disc keeps filling. I know, manager them! Here is a little trick to find the large offenders if you are going through the same thing.
# du -a /var | sort -n -r | head -n 10
That line will show you the top 10 largest file/directories is taking up the most space in a /var directory/file system. If you want to search other directories, just modify the /var path to the path you wish to search.
Hope it helps someone!
Rob