Back-UPS garbage? (was: Quick survey -- UPSs on slave nodes?)

[Robert G. Brown]

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
rarer...

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;-)

   rgb

-- 
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