组合盘中结合访问次数与能量代价的文件缓存替换策略

Frequency and Energy-Based Replacement Scheme for Heterogeneous Drive

如何有效地降低存储子系统能耗是近几年研究的热点议题。新型非易失、抗震、低功耗闪存及固态盘的出现给存储子系统节能带来了新的机会。但其每单位价格昂贵,目前难以替代硬盘的角色。结合硬盘和固态盘的优势,本文采用组合盘(由硬盘和固态盘组成)节能。结合文件访问次数和能量代价,我们提出了改进的文件缓存替换策略FEBR(Frequency&Energy-based replacement)。实验采用两个真实办公用户数据,结果表明组合盘方案是可行的,节能百分比可达70%～80%;与经典替换算法、最新较好的ARC算法以及理想最优页面OPT算法进行了详细比较,FEBR优于其它策略。

How to reduce the energy consumption of storage sub-system effectively has gained a lot of attention these years. The emergence of non-volatile, shock resistant and low power flash memory and solid state driver （SSD） brings a new opportunity for power-saving in storage sub-system. However, it still cannot totally replace hard disk for its higher cost per storage unit. This paper focuses on the heterogeneous drive scheme （heter-Drive for short） for both energy-conservation. By considering both file access frequencies and energy cost, we propose an improved file cache replacement scheme called FEBR （Frequency and Energy-based Replacement）. We collected four real-world office users＇ file access data for experiments. The results show that heter-Drive does works well and saves as high as 70% 80% of energy; the extensive comparisons with the classic replacement algorithms, the widely used ARC and the optimal algorithm OPT show that FEBR is consistently better than other alternatives.