基于I/O空闲率的硬盘功耗建模与评估方法研究

Disk power module and evaluation based on I/O idle rate

存储设备的功耗在整个计算机系统尤其是数据中心所占的比例已经越来越大。要进行硬盘功耗优化,在缺少硬件直接测量硬盘功耗的情况下就需要对硬盘功耗进行建模。现代操作系统通过文件系统层进行硬盘I/O操作管理,并提供实时监控数据。通过对EXT2、EXT4和NILFS2等常用文件系统的硬盘I/O过程进行实验分析,发现不同的文件系统对硬盘功耗具有不同的影响,为了刻画这种差异性,提出基于I/O空闲率的硬盘功耗建模与评估方法。同时使用I/O空闲率来指导硬盘进行功耗优化,将视频播放器的I/O空闲率由4.79%提高到96.55%,硬盘的功耗降低45.28%。

Storage is consuming more and more energy in computer, especially in data center. In order to reduce disk power, it needs to establish the disk power module when there no hardware to measure the power. Modern operating system uses file systems to manage I/O and provide real-time monitoring data. This paper analyzes the I/O processing of EXT2, EXT4 and NILFS2 file systems, and discovers that different file systems have different influence on disk power. This paper presents I/O idle rate to depict the difference, more specifically, proposes the disk power module and evaluates method by using I/O idle rate. This paper also uses I/O idle rate to reduce disk power, when improving the I/O idle rate of video from 4.79%to 96.55, reducing the disk power 45.28%.