What is the limit? (was RE: multi-homing fixes)

I have been trying to avoid saying this, but this is just nonsense with
a little srinkle of "doesn't matter" here and there.

Actually, talking about water/electricity interaction in refrigerators,
lab equipment, etc, misses the very simple point - a probability of a leak
is proportional (as a good approximation :slight_smile: to the number of moveable
components (PCBs, connectors, etc) in the system. In a typical CO it's
tens or hundreds of thousands.

I don't remember seeing anybody talking about lab equipment and refrigerators
here.

We (some of us) were talking about liquid-cooled electronics, some of them
were talking about actual experience--mine with water-cooled CPU's.

PS. Water is not a good coolant, and even distilled and deionized
        water tends to pick ions from metal parts rather quickly. Spirits
        are flammable; CFCs are bad for environment. There's also an
        issue of toxicity.

Water is one of the better coolants--particularly when cost is considered.
The rest of that is one of the sprinkles I mentioned--water can in fact be
toxic, see http://www.dhmo.org/

In the real, actual world, the coolant is in its own circulation system
(like houses, engines, and such), so cruft in the water is no more than
a maintenance issue every some large number of hours.

  Of course, everything is doable, but what is the cost?
        Off-the-shelf components are all designed for air cooling.
  Switching to liquid cooling means a lot of custom stuff; which is
  expensive and which takes a long time to design and manufacture.

As I recall the electronic components in a water cooled 1100/90 CPU
were as "off-the-shelf" as anything else in the machine, including most
of the water system. No more "custom stuff" any "branded" equipment,
I'd say.

PPS It is not voltage which matters, it's current :slight_smile: Even if leaks do
        not cause shorts the moisture accumulation may corrode parts
        leading to mechanical shorts, it also may cause excessive
        cross-talk. Sporadically malfunctioning equipment is much worse
        than flat-out burned out.

Not sure what this all means. Yes, we did have failures due to water leaks.
Idjits on the floor above us neglected to put the plun in the bottom of
their water tanks and pour a lot of water on us!

PPS Finally, getting your hands wet makes your changes to get killed
        by electricity _much_ higher. 48V won't do you any harm if your
        hands are dry, it may kill if they're wet.

Als true--but then we were always careful to dry our hands before leaving the
restroom. And checking the folks upstairs if we saw water bottles on the dock.

I have been trying to avoid saying this, but this is just nonsense with
a little srinkle of "doesn't matter" here and there.

You're not the first to tell that i'm talking nonsense; but i had both
experience with a water-cooled computer (not something i wish to repeat),
_and_ designing hardware for COs (heck, the first computer i laid my hands
on was using thyratrones (sp?) for triggers, and quite a few relays).

> Actually, talking about water/electricity interaction in refrigerators,
> lab equipment, etc, misses the very simple point - a probability of a leak
> is proportional (as a good approximation :slight_smile: to the number of moveable
> components (PCBs, connectors, etc) in the system. In a typical CO it's
> tens or hundreds of thousands.

I don't remember seeing anybody talking about lab equipment and refrigerators
here.

Archives are at www.nanog.org.

We (some of us) were talking about liquid-cooled electronics, some of them
were talking about actual experience--mine with water-cooled CPU's.

Not everything which works in one-of-a-kind supercomputers is workable in
your average central office. People who build equipment which has to work
for years w/o interruptions, survive quakes, power faliures and
thick-fingered technicans are not idiots; and if water cooling was a real
solution for CO environmental control woes, they'd use it.

In an average CO a poodle on a floor has a risk of not being noticed for
a couple of months. It doesn't have an alarm relay, you see?

(Have you ever seen a blast of H2/O2 mix resulting from electrolysis? No?)

--vadim

I gaurantee you (and I'm no CO expert) but after 1 week of leaving a
dog inside a CO someone will probably about it. :wink:

-Jim P.

I know somebody who had the misfortune of having to post to an 'outages'
mailing list that they were going down because a racoon had gotten in
via a construction zone and was loose under the raised floor.

He had the added misfortune of finding out about said racoon about 8PM
on March 31. So of course everbody got the mail the next morning...

/Valdis

If money is no object, use Flourinert. Non conductive, non
corrosive.

Joe