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Re: [OM] Data Center going bye-bye

Subject: Re: [OM] Data Center going bye-bye
From: Ken Norton <ken@xxxxxxxxxxx>
Date: Tue, 26 Aug 2014 17:39:33 -0500
> I'm glad I don't have to manage it.  To show my age I go back to the time
> where not only did the cables run under the floor... so did 4" pipes
> carrying de-ionized water for cooling.  I remember lifting a tile one time
> and finding several inches of water under the floor from a broken pipe
> fitting.  It's the only time I've ever hit the Emergency Power Off button.
> :-)

De-ionized water will barely cause a short, but that was probably a
good thing to hit the power off button.

There was a spectacular data center fire a few years ago that happened
down in the raised floor. The halon system went off, but didn't do
squat for the fire in the floor because air feed was pumping in fresh
air down there. Then the sprinklers went off and still didn't snuff
out the fire because what water did enter the subfloor was drained
away. At some point the gasses from the burning cables did a flash
over and the entire floor erupted in flames and the explosion from
that threw manyof the tiles up in the air and knocked over equipment
racks. On a positive note, the firefighters were then able to put the
fire out, but still required ripping up almost the entire floor to get
everything out. Then cleanup and room gutting was all the more
difficult.

Back when I was in college, majoring in IT and accounting, I edited a
college textbook on facilities management. I was working for a college
prof, who had a side publishing business and this book was for some
Ivy League professor. I believe that this textbook was the first
published work that was actually quite critical of raised flooring and
dealt with many issues that later came to light with the Hinsdale
fire.

Plenum spaces are great for many things, but running thousands of
wires through them with no means for fire suppression? Really?

I've been in probably 300 data centers, carrier hotels and telephone
switching offices. There are several common problems that keep showing
up:

1. Suspended ceilings with wiring run up there. No sprinkler systems
in that space.
2. Raised flooring with wiring run down there. No sprinkler systems
able to protect that space.
3. Really high ceilings with sprinkler systems too low. Flash-over
passes above the sprinklers.
4. Intermingled power and communication wiring. Not good, folks.
5. Main power cutoff for the DC plant not located in an easily
reachable place. Power converters, batteries, air handler controls and
main power switches located inside the main equipment room itself.
6. Cable raceways with too solid a mass of wiring. No ability for
overheating wiring to disipate the heat and acts as a block for water.
7. Fully enclosed reinforced-concrete room. No ability to vent heat
and smoke during a fire. Smoke is actually fuel for additional
burning. The new FB data center in Iowa is specifically designed to
address this issue.

Modern data centers look a lot like warehouses inside. The floors are
concrete (raised above surrounding plain, with multiple drainage
systems). Usually covered with waxed flooring tiles because concrete
emits dust. The relay racks are bolted into the floors and if in
seismic zones, the racks are also anchored to overhead steelworks.
Actually, most of them are anchored anyway. Cabinets are usually just
bolted to the floor. The overhead steelwork has usually three tiers of
cabling. Power is one one tier, communications cables on another tier
and fiber on another tier running in "gutters". Typically, two of the
tiers are actually on the same level, but staggered on front and rear
of the ladder racks.

In Telecom switching offices, the bulk of the power is -48 volt DC. In
data centers, it's 240v AC. The advantage in cabling size is huge, and
you don't get the thermal issues either. You'll find in most telco
co's the cables are all randomly "tossed" in the raceways and look a
mess. That's done on purpose to prevent cross-talk and also to keep
cables from overheating.

In the majority of our raised-floor installations, we've since gone
through and mined out all the cabling and brought it out overhead.

Last, but not least:

8. Placing the data center right near the end of an airport runway.

AG
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