The important metrics for storage equipment are power consumption (kVA) /heat production(kWatts) and power loading (kVA/sq.ft.)/heat loading (kWatts/sq.ft.). The kVA and kWatt figures will allow the cost of power and cooling to be calculated. The kVA/sq.ft. and kWatts/sq.ft. figures will establish if sufficient power and cooling is available in the data center. The important trend for storage is that the power and heat densities are going up. Controller technology is getting denser, and the move from 3.5” to 2.5” disk technologies will increase drive power densities.
The current power density for high-end storage is about 0.7kVA/sq.ft. Wikibon projects predicts that this figure will increase to over 2kVA/sq.ft. over the next five years. This figure is not as high as projections of over 10kVA/sq.ft for racks of 1µ server blades, but most data centers have power densities of significantly less that 1kVA/sq.ft at present.
Action Item: Storage vendors (perhaps under the leadership of organizations like SNIA) should give clear guidance on future power and heat metrics. IT departments need to plan now for significantly high power and cooling densities in the data center.
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