MAID – Massive Array of Idle Disks to store persistent but little-used data on mostly spun-down disks. Envisage a disk array with a cache of spinning drives and a residual archive of idle, non-spinning drives. The idea is to have a faster access archive than a tape library with lower electricity draw than an array of fully spinning drives. If a data read request is not present on the cache drives, then the data is located on an idle drive and it is spun up and then the data accessed. Startup Copan used the MAID concept in its disk drive arrays in the late 2000s but crashed. Its assets were bought by SGI which persisted with the technology in 2010. It didn’t take off.