[Beowulf] Re:UPS system for Linux cluster

[Gus Correa]

Huw Lynes wrote:
> On Wed, 2009-04-29 at 11:21 -0700, John Bushnell wrote:
> 
>> Another reason for not having UPS power for an entire cluster is 
>> cooling.  In our server room, if we lose regular power, we lose our 
>> large AC units as well.  So we need to be careful what we keep plugged 
>> into our emergency power circuits (a relatively tiny amount of 
>> equipment).  Having an entire stack of nodes churning away during a  
>> power outage would kill us pretty quickly.
> 
> 
> The alternative approach is to UPS everything. Which is what we do.
> Although we only have a short run-time installed which will bridge us to
> the diesel generator.
> 
> In the event that the diesel doesn't kick-in the cluster will cleanly
> shut itself down and wait for the UPS to tell it everything is back to
> normal (or until an admin intervenes, whichever comes first).
> 
> Thanks,
> Huw
> 

Hi Huw, list

Same here.
We have aerial power lines, which collect fallen tree branches,
lightning, and electrocute squirrels all year long.
Brownouts and power outages happen on a daily basis.
No UPS and no diesel generators would mean no work done
and hardware damaged too often for us.
They protect computers and lab sensitive equipment.
In areas of clean and steady power supply one can probably
live without UPS and generators, though,
if the computers and other equipment
are not high-availability or mission-critical.

Gus Correa
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Gustavo Correa
Lamont-Doherty Earth Observatory - Columbia University
Palisades, NY, 10964-8000 - USA
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