Trying to write to a full disk may not crash Unix, but on 4.2bsd
typing ^S to the resulting "filesystem full" messages will freeze
all of the ttys (and the console) until you type the corresponding ^Q.
(Fortunately rshd doesn't use pty's).
Don Speck speck at vlsi.caltech.edu {amdahl,ames!elroy}!cit-vax!speck