Energy-Aware Scheduling in Disk Storage Systems

This paper deals with the problem of scheduling requests on disks for minimizing energy consumption. We first analyze several versions of the energy-aware disk scheduling problem based on assumptions on the arrival pattern of the requests. We show that the corresponding optimization problems are NP-complete by reduction to the set cover or the independent set problem. Then both optimal and heuristic scheduling algorithms are proposed to maximize the energy saving of a storage system. Our evaluation results using two realistic traces show that our approach significantly reduces energy consumption up to 55% and achieves fewer disk spin-up/down operations and shorter request response time as compared to other approaches.