Back-UPS garbage? (was: Quick survey -- UPSs on slave nodes?)
Robert G. Brown
rgb at phy.duke.edu
Mon Feb 10 16:30:53 PST 2003
On Mon, 10 Feb 2003, Drew Raines wrote:
> <alvin at Maggie.Linux-Consulting.com> writes:
> > $40 el cheapo APC for each node...
> I assume you're referring to the ``Back-UPS'' line. The only thing
> I've found those to be able to support on battery power is my clock
> radio, which I could more easily protect with a 9-volt.
> Has any one of you actually used these to sustain a PC for any
> measurable length of time? I'm not sure at what market this junk
> is aimed, perhaps suckers.
In the Durham NC residential grid we have a power outage that lasts
approximately one second approximately once a month. One second is just
about exactly what it takes to crash a computer (or a digital clock, or
a digital coffee maker, or...grrr). Maddening, as somebody is ALWAYS
doing something critical right when the power bobbles -- just for a
second. Crash. Boom. There goes the homework.
I've recently started putting my home computers (which are all members
of my home cluster:-) on $50 cheap UPS because they are enough to
sustain a system across these frequent, short, outages. I don't need
even minutes -- just a few seconds worth of protection. Minute or
longer outages are MUCH rarer, and tend to be associated with things
like ice storms, hurricanes, nuclear disasters. Well, not THAT much
I also was motivated by a home system that blew power supply,
motherboard, hard disk and at least three cards. Maybe it was a surge,
maybe not, but a cheap UPS is also a good surge protector, and only $20
more than a good surge protector alone.
So far, the two I've gotten have worked fine through a few of these
short outages, and I'll probably get one more (as I still have one
computer without one). I don't know if I'd try scaling up to a whole
"real" cluster this way, though -- there are more cost effective ways to
do cluster nodes;-)
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:rgb at phy.duke.edu
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