Command line to find large files in linux

gistfile1.txt

Find top 20 largest files starting at root directory
du --exclude=/proc* -a / | sort -n -r | head -n 20

List the size of of the folders in the current directory
du -hsx * | sort -rh | head -10

Checks processes that are keeping deleted files open
lsof -s | grep deleted | sort -k 8

Check rotation of error logs ... as it is not working large files are being created
logrotate -d /etc/logrotate.conf

Cool check that will give the totals of each folder in the root directory as well as the total space being used by the server. 
.. if not being used there then it is probably a process maybe using a deleted file
du -x   -d1 -h /