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Power, But Not Too Much Power

Members of the ISP-Colo list discuss how to monitor colocated customers' power use. Methods range from a simple amp meter to a full-blown telco-level deployment.

[February 14, 2002]

On the ISP-Colo list in January, DK inquired,

"As business has picked up at our colo facility, we've gone from little guys with one or two servers to people who buy entire racks. Now, with 500 servers, we feel like we need to manage our power a little better. How do you measure and manage your customers' power usage?"

There was some disagreement as to whether or not a simple amp meter would do it:

[AD suggested] "Wouldn't an amp meter work?"

[JP recalled] "I tried an amp meter for a while, but once the number of customers got too high, it was no longer a viable option."

EC advised taking a look at the way Verizon handles the issue:

"You might find some useful information in Verizon's tariffs. Maybe it isn't the best model, but it's a start. One good example is Verizon's Massachusetts DTE Tariff No. 17, available at here, in .pdf format."

Others recommended some specific solutions:

[AR observed] "Square-D has a system that will essentially become a part of any QO type load center for power distribution: it will measure every branch, and is SNMP-queryable [definition]."

[RS noted] "We use a rackmounted power strip that we can Telnet into; we have a script that queries this every half hour and does a graph for us. Always use some sort of automated system to tell you what your true power usage is: graphs are good for growth and management."

[JP offered] "I did one read on all the circuits in my center, and averaged the draw. Then I calculated our cost per circuit, uplifted a percentage, and came up with a price to charge our customers. Once a quarter, we take a read of a few circuits to verify that our pricing is still relevant. It's a low cost solution when it isn't viable to purchase monitors."

—End