If they can be avoided, why do we put up with them?
Major electrical fire, or arcing in the datacenter. Flood in the datacenter. Accidental water sprinkler discharge in the datacenter. Equipment fire that the FM-200 didn't put out, and you want not to have the sprinklers go off if you can avoid it. Equipment fire in a room without FM-200 in the first place. Equipment fire with sprinkler discharge, and you'd really rather just dry out the equipment than have to replace it all. Electrical worker who's electrocuted himself and going to die if you can't make the power go away. There are a very few exceptions, but for our practical purposes, people really ought to simply go to multiple site redundancy rather than thinking about bending major safety assumptions in how we operate individual buildings. You may have a few less outages, but you may also kill someone. What the Navy does on ships, for critical ship safety and combat systems; what the FAA does for their radar facilities and air traffic control facilities; what Telcos do, these are different operating regimes, and there are associated higher risk acceptance with the different equipment setups and safety procedures. -george william herbert gherbert@retro.com