Electronic International Standard Serial Number (EISSN)
Energy saving for computing systems has recently become an important and worrying need. Energy demand has been increasing in many systems, especially in data centers and supercomputers. This article considers the problem of saving energy on storage systems taking advantage of SSD drives. SSD and magnetic disk devices offer different power characteristics, being SSD drives much less power consuming than conventional magnetic disk drives. This paper presents the design and evaluation of a novel power consumption-aware prefetching mechanism for hybrid storage systems. The prefetching mechanism aims to reduce the power consumption of high performance storage subsystems. Every disk access request is absorbed by an associated SSD device, and only when the SSD device is full, requests are forwarded to the disk in background. We have evaluated the proposed approach with the help of both synthetic and realistic workloads. The experimental results demonstrate that our solution achieves significant reduction in energy consumption. Additionally, the performance evaluation shows that our solution may bring a substantial I/O performance benefit.