Wanna kill your filer? Put lots of big directories with lots of files in there, then watch the nfs server not responding messages start up.
I have an F540, 256MB RAM, and 8MB NVRAM that is just getting wiped out with numerous large directories. (~40-50k files/dir). Hangs of 20-30 seconds are not uncommon, sometimes as long as 3 minutes.
Needless to say, we are not amused.