Measuring power

[Adrian Lai]

2009/4/29 Andrew Beattie <andrew at tug.com>:
> This is a long way off topic but I'm hoping that someone here might be able
> to share a clue...
>
> I need to measure the power used on dozens and dozens of servers.
>
> I need a breakdown by server, not a total for the room.
>
> (more specifically, I want to calculate the power cost per server per year).
>
> Added difficulty:  I want to do this non-intrusively.
>
> I can't go round, yanking out cables and inserting in-line meters.
>
> So, I got a clamp meter.  But contrary to my expectation, that only works if
> I can separate the individual wires in the power cable - not an option.
>
> So, I'm stuck.  Is there any non-intrusive way to measure the power
> consumption of my servers?
>
> Andrew
>

Do you need exact figures?

And, by non-intrusively, do you mean from a software point of view as well?
I'm thinking a utility like powertop could be of use, although I'm not
sure how well that would compare with losses in the PSU and fans and
suchlike.
Presumably you could use an in-line meter for one server, and use this
to work out a best guess for others.

Adrian.