Semantic Data Placement for Power Management in Archival Storage

Power is the greatest lifetime cost in an archival system, and, as decreasing costs make disks more attractive than tapes, spinning disks account for the majority of power drawn. To reduce this cost, the authors propose reducing the number of times disks have to spin up by grouping together files such that a typical spin-up handles several file accesses. For a typical system, they show that if only 30% of total accesses occur while disks are still spinning, they can conserve 12% of the power cost.