that sound you get when...
the n00b* forgets that soft bypass on the ups is not actually full bypass and they cut the power to do inverter maintenance
or should i say, the sound you don't get
from anything
server rooms are really quiet when things are not powered on.
*this may or may not have happened to me in a former incarnation, but seemingly at my last job it was a rite of passage for everyone no matter how well we trained them and documented it
Biting the hand that feeds IT
