Some guy at some substation does the wrong thing, and then half my state and the ones next door go dark

I'll go download Mendel Cooper's bash programming guide I've used countless times, just in case.
http://tldp.org/LDP/abs/html/

zones also make sense with resource constraints (containers) if you want to license Oracle or something else that costs per processor. Most low end server class boxes now come with more cores than lots of small-medium businesses can fork over the Oracle licensing cost for.