Re: 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 :) 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 :) 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.
On Thu, 30 Aug 2001, Larry Sheldon wrote:
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 :) 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
--- Vadim Antonov <avg@exigengroup.com> wrote:
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?
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. ;) -Jim P. __________________________________________________ Do You Yahoo!? Get email alerts & NEW webcam video instant messaging with Yahoo! Messenger http://im.yahoo.com
On Thu, 30 Aug 2001 22:30:40 PDT, Jim Popovitch <jimpop@yahoo.com> said:
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. ;)
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 -- Joe McGuckin ViaNet Communications 994 San Antonio Road Palo Alto, CA 94303 Phone: 650-213-1302 Cell: 650-207-0372 Fax: 650-969-2124
participants (5)
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Jim Popovitch
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Joe McGuckin
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Larry Sheldon
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Vadim Antonov
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Valdis.Kletnieks@vt.edu