Understanding the relationship between energy conservation and reliability in parallel disk arrays

Energy conservation schemes based on power management or workload skew for disk arrays adversely affect disk reliability due to either workload concentration or frequent disk speed transitions. A thorough understanding of the relationship between energy-saving techniques and disk reliability is still an open problem, which prevents effective design of new energy-saving techniques and application of existing approaches in reliability-critical environments. This paper presents an empirical reliability model, called PRESS (Predictor of Reliability for Energy-Saving Schemes). Fed by operating temperature, disk utilization, and disk speed transition frequency, PRESS estimates the reliability of an entire disk array. Further, a new energy-saving strategy with reliability awareness named READ (Reliability and Energy Aware Distribution) is developed in the light of the insights provided by PRESS. Experimental results demonstrate that READ consistently performs better than existing approaches in performance and reliability while achieving a comparable level of energy consumption.

Research highlights
► Understanding the relationship between energy-saving techniques and disk reliability.
► An empirical reliability model PRESS estimates the reliability of a disk array.
► A new energy-saving strategy with reliability awareness called READ.
► READ consistently performs better than existing approaches in reliability.