At an IBM UK event today to discuss energy-efficient data centres a UK consultant said IBM was examining technology to turn disk drives off if they were not needed. Is he talking MAID service?

He explained that data that was not accessed very much did not need to be on constantly spinning disks. Indeed not. So IBM was examining technology to turn the disks off when not needed.

IBM is in the Green Grid. So too is Copan, lovely little Copan with its MAID technology which does what IBM wants. Just as IBM's BladeCentre can house dense sets of server blades, Copan MAID arrays can house dense sets of disks, the densest in the world actually. The company has just started shipping arrays with 750GB SATA drives. That means Copan arrays can house up to 672TB, a storage density of 67.2TB/sq ft.

That's raw data by the way. Copan is adding de-duplication technology which could shoot that total up to 10 or 20 times meaning 13.44 petabytes of raw persistent data could be crammed into one Copan array and take up the full 672TB of actual disk blocks. That is an effective storage density of 1.344 petabytes/sq foot if my math is correct.

Nothing else comes close. The energy savings could be 70, 80, 90 percent or more per unit of storage compared to using traditional arrays to store the same data. That could mean a 10 to 20 percent reduction in overall storage energy costs, possibly more.

Copan has an energy savings calculator web page. You might care to try it out. In terms of big wins for data centre power consumption Copan arrays provide it for businesses with lots of persistent data they need to keep online.

The IBM'r did not say IBM was talking to Copan. (Copan is also talking to Sun by the way.) But what other technology could IBM be examining?

Copan is a privately-held company with venture capital funding; always looking for a profitable exit those guys. Nothing is quite as profitable as the acquisition by a big IT supplier of a newcomer with technology whose time has come. Maybe a trouser pocket-filling crystalisation is coming for the Copan venture capitalists.