useful linux commands for non sys admins

We just had a minor crisis with our dedicated server (thanks to Fasthosts sceurity breech and the subsequent roor password changes) and I’ve learnt these new shell comands:

postfix flush

flushes the mailqueue

du --max-depth=1 /home/ | sort -n -r 
lists the sizes of folder when you cannt work out where all the massive log files are located!

find /home/default/ -name '*.*' -print0 | xargs -0 rm
deletes all our stored spam  (when you have over 100,000 to delete and normal rm dosnt work!)

I hope this is useful for someone.