Facebook is now experimenting with a storage prototype that uses racks of Blu-ray discs instead of hard drives. The discs are held in groups of 12 in locked cartridges and are extracted by a robotic arm whenever they’re needed.

One rack contains 10,000 discs, and is capable of storing a petabyte of data, or one million gigabytes.

via Why Facebook is stockpiling Blu-ray discs – Aug. 21, 2014.