Up to one third of the electricity supplied to a data center is required for the operation of the storage subsystem. A typical data-center workload, characterized by short idle periods, prevents traditional disk power management (DPM) from saving energy. This paper starts with an analysis of DPM's traditional timer-based disk spin-down policy. Next, we examine how a multispeed disk adapts DPM to data-center workloads. Finally, we determine how to shape the workload to enable DPM on conventional server disks. All analysis is based on an analytical model for the energy consumed by a disk during an idle period. In addition, we assume standby power to be non-negligible. The results are that (1) the competitive ratio of a threshold-based disk spin-down policy depends on the ratio of standby power to idle power, (2) the notion of break-even time can be generalized for multispeed disks, and (3) DPM saves most energy when mean idle time and idle-time variance are maximized. With this analysis, the authors intend to stimulate the design of new data-center file and storage systems that optimally exploit DPM to save energy.
|Title of host publication||Proceedings of the third International Conference on Future Energy Systems: Where Energy, Computing and Communication Meet (e-Energy 2012)|
|Place of Publication||New York|
|Publisher||Association for Computing Machinery (ACM)|
|Number of pages||10|
|Publication status||Published - 11 May 2012|
Bostoen, T., Mullender, S. J., & Berbers, Y. (2012). Analysis of disk power management for data-center storage systems. In Proceedings of the third International Conference on Future Energy Systems: Where Energy, Computing and Communication Meet (e-Energy 2012) (pp. 2). New York: Association for Computing Machinery (ACM). https://doi.org/10.1145/2208828.2208830