Facebook has designed an optical data storage array using Blu-ray disk technology, delivering high data density, very low power use, and long storage life.
I remember talking to optical storage industry people back in 2005, when they were considering whether to try and get into the data center storage market (using DVDs). The upshot was that the industry focused solely on consumer products, and of course hashing out the next optical disc standards.
The prototype rack holds 10,000 Blu-ray disks in magazines, using mechanical means to access and read the disks, very much like a tape magazine system. The array holds a petabyte of storage, and uses eighty percent less energy than Facebook's other "cold storage" innovation, which is essentially a data center-scale MAID system.
(The data center-scale MAID system is a separate room for data "cold storage", where rarely-accessed data is saved on hard drives which are then shut off. You can get the data back, but with somewhat slower access times. By housing the equipment in dedicated rooms, the environmental conditions can be set far wider than for other data center IT equipment, delivering greater energy savings.)
There is other news from the conference this week that is of interest to data center energy efficiency junkies, but Facebook deserves lots of credit over the years for exploring data storage options. They made use of rack scale MAID systems years ago, and continue to lead the way with these new schemes.
I think there are real opportunities for utility energy efficiency program offerings in the data storage space, despite some challenges. At the very least, there is an opportunity to educate customers about energy efficiency options, and I think an incentive program could be developed to support the adoption of solid state, and now optical, data storage technologies.