Someone used "STONITH - Shoot the other node in the head" - what a silly acronym.  

I like SHS better - Sending Head-Shot - in the time-honored tradition of FPSes (First-Person Shooters) like CSS (Counter-Strike: Source) where head-shots are the name of the game (and a source of all too much frustration).  

Plus, it's pronouncable: "shush," as in "shush that server - it's gone tits up and is slowing down the cluster!"