On Tue, 17 Apr 2007, David Mathog wrote:
"Peter St. John" <[EMAIL PROTECTED]> wrote:
4. Physicist who builds his own damn Supercomputer agonizes for days over
the emergency shut off switch wiring, because he can, he teaches
electricity; but he could just walk one hundred yards down Science
Drive and
get an EE grad student to do it for him.
The problem with the Emergency Stop switch is not designing or
building the electrical wiring to implement it, it's interpreting
the electrical code to determine if one is required. Parts of the
code were apparently written by a Zen master so that the answer to
what seems like a straighforward question "do we need an
Emergency Stop switch?" depends on the answer to "is this room full
of machines a machine room"? The latter is apparently an
electrical code koan, as only the enlightened can divine the answer.
And maybe not even then - there seems to be room for considerable debate
on the issue. Indeed, the answer may depend not so much on what
the room holds, but rather on how it was wired, as certain sections
of the code may be "relaxed" in machine room construction.
The Zen cluster geek asks, ``What are the parallel computations done by
a one-node cluster'' and spends the next twelve years (four three year
federal grant cycles) seeking an answer. While doing so he completely
forgets to shower or do laundry, let alone worry about kill switches.
In year eleven he is Enlightened, unplugs his cluster and goes to live
under an overpass on I95 southbound, occasionally using a solar-powered
scientic calculator to compute the roots of a Riemann Zeta function to
ten significant digits.
I personally think it is more voodoo than Zen. If the room has
witnessed the sacrifice of at least one chicken per rack and has a
voodoo doll of Bill Gates hanging upside down from the network wiring
tray, and a Loa has been invoked to protect the server's power supply,
then it is a machine room. Otherwise it's just a broom closet with a
lot of computers in it.
Suffice it to say that a definitive "required" or "not required"
has not yet been obtained from the folks in charge of the room's
construction.
Ah, but we should never forget that the >>definitive<< requirement will
only be known >>after<< resolving the lawsuit filed by the survivors of
the dead firemen >>or<< after the inspector man (if any) ever declaims
"you must have a kill switch" whichever comes first. So the question
is: Do you feel lucky? Well, punk, do ya?
rgb
Regards,
David Mathog
[EMAIL PROTECTED]
Manager, Sequence Analysis Facility, Biology Division, Caltech
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--
Robert G. Brown http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567 Fax: 919-660-2525 email:[EMAIL PROTECTED]
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