[mrtg] Info off of a UPS

[Jay Hennigan]

Mike Murphy wrote:
> Hello,
>  
> we are trying to get some information off of a building UPS system  I 
> have the mibs and all but the graph does not show what we are looking 
> for. we are trying to graph kilowats used any chance you can tell me 
> what I ahve wrong here??
> thanks  Mike

You can create a custom target for each phase where you multiply the 
voltage and the current (in or out) to get volt-amperes which will be a 
relatively close indication of watts.  This depends on the reactive 
characteristics of the load but for typical datacenter use will be 
fairly accurate.  Divide by 1000 to get kilowatts, but I'd leave it as 
watts.  MRTG has only integer granularity and the graphs will scale 
appropriately so leaving it as watts will give more precision.

Or, you can multiply the amperes by the nominal voltage at the 
input/output (120, 208, etc.) for a rough approximation.  Voltage is 
relatively constant, current varies with load.  Output voltage is 
regulated by the UPS, input is whatever the utility gives you.  For a 
three-phase or split-phase unit you'll need to add the phases together 
for a total.

Note that watts or kilowatts is a measure of the power consumed by the 
UPS or load (depending on which MIB you poll) at any given sampling 
instant.  It is, as was pointed out others, not useful for energy 
billing purposes.

--
Jay Hennigan - CCIE #7880 - Network Engineering - jay at impulse.net
Impulse Internet Service  -  http://www.impulse.net/
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