[Back] [PDF]  Improving Reliability and Energy Efficiency of Disk Systems via Utilization Control Kiranmai Bellam†, Adam Manzanares†, Xiaojun Ruan†, Xiao Qin†*, and Yiming Yang‡ †Department of Computer Science and Software Engineering Auburn University Auburn, Alabama 36830, USA {kzb0008, acm0008, xzr0001}@eng.auburn.edu, xqin@auburn.edu   ‡Intel Corporation Rio Rancho, NM 87124 yiming.yang@intel.com As disk drives become increasingly sophisticated and processing power increases, one of the most critical issues of designing modern disk systems is data reliability. Although numerous energy saving techniques are available for disk systems, most of energy conservation techniques are not effective in reliability critical environments due to their limitation of ignoring the reliability issue. A wide range of factors affect the reliability of disk systems; the most important factors – disk utilization and ages – are the focus of this study. We build a model to quantify the relationship among the disk age, utilization, and failure probabilities. Observing that the reliability of a disk heavily relies on both disk utilization and age, we propose a novel concept of safe utilization zone, where energy of the disk can be conserved without degrading reliability. We investigate an approach to improving both reliability and energy efficiency of disk systems via utilization control, where disk drives are operated in safe utilization zones to minimize the probability of disk failure. In this study, we integrate an existing energy consumption technique that operates the disks at different power modes with our proposed reliability approach. Experimental results show that our approach can significantly improve reliable while achieving high energy efficiency for disk systems.   This paper appeared in the Proceedings of the 12th IEEE Symposium on Computers and Communications (ISCC'08), Marrakech, Morocco, July 2008. * Acknowledgments The work reported in this paper was supported by the US National Science Foundation under Grants No. CCF-0742187, No. CNS-0757778, No. CNS-0831502, No. OCI-0753305, and No. DUE-0621307, and Auburn University under a startup grant.