History of the EPO (Emergency Power Off)

Thu Jul 26 00:10:53 UTC 2007

The interesting thing about the EPO and data centers is it wasn't 
orginally for life-safety, but came out of a recommendation by IBM
to the NFPA for property protection.

But like many things, the original reasoning been lost to history, and 
the codes grew in different ways.

http://www.datacenterknowledge.com/archives/2007/May/07/averting_disaster_with_the_epo_button.html

   The history of the emergency power off switch dates back to 1959, when a
   fire in the Air Force's statistical division in the Pentagon caused $6.9
   million in property damage and destroyed three IBM mainframe computers.
   "Nothing gets the government.s attention like something that happens to
   government," said Sawyer. The National Fire Protection Agency (NFPA) was
   tasked to develop rules to address fire risks in IT environments.

Sometimes you need to revisit the rules.  For example, for folks
thought having automatic water sprinklers in data centers was a bad thing. 
Slowly folks have started to rethink it, and now automatic sprinklers are
found in more data centers.  I don't have hard data, but my experience
is there have been fewer outages from accidental sprinkler discharges
than from accidental EPO activations.