Performance Evaluation of Energy-Efficient Parallel I/O Systems with Write Buffer Disks

Abstract

Abstract-In the past decade, parallel disk systems have been developed to address the problem of I/O performance. A critical challenge with modern parallel I/O systems is that parallel disks consume a significant amount of energy in servers and highperformance computers. To conserve energy consumption in parallel I/O systems, one can immediately spin down disks when disk are idle; however, spinning down disks might not be able to produce energy savings due to penalties of spinning operations. Unlike powering up CPUs, spinning down and up disks need physical movements. Therefore, energy savings provided by spinning down operations must offset energy penalties of the disk spinning operations. To substantially reduce the penalties incurred by disk spinning operations, we developed a novel approach to conserving energy of parallel I/O systems with write buffer disks, which are used to accumulate small writes using a log file system. Data sets buffered in the log file system can be transferred to target data disks in a batch way. Thus, buffer disks aim to serve a majority of incoming write requests, attempting to reduce the large number of disk spinning operations by keeping data disks in standby for long period times. Interestingly, the write buffer disks not only can achieve high energy efficiency in parallel I/O systems, but also can shorten response times of write requests. To evaluate the performance and energy efficiency of our parallel I/O systems with buffer disks, we implemented a prototype using a cluster storage system as a testbed. Experimental results show that under light and moderate I/O load, buffer disks can be employed to significantly reduce energy dissipation in parallel I/O systems without adverse impacts on I/O performance.

Cloud Computing

“…Using DRPM [Gurumurthi et al 2003] with dynamic spin speed may represent a more flexible solution for gradually scaling the performance of a disk. Other energysaving techniques include MAID [Colarelli and Grunwald 2002], BUD [Ruan et al 2009a], EERAID [Li and Wang 2004], and PDC [Pinheiro and Bianchini 2004]. Choosing the right processor architecture can also contribute to more efficient energy usage.…”

eWave

“…An off-loaded block is copied to its target volume when this volume becomes active because of a read-cache miss. In this line, authors in [36] study the use of write buffers in a parallel I/O storage system to reduce power consumption. The present paper extends these works providing a analytical energy model of deferred writes.…”

Lazy scheduling based disk energy optimization method

“…Sehgal et al [39] evaluated the impact of the file system upon server performance and energy. Ruan et al [40] used log files to cache small data, delay disk shut-down time, and reduce disk energy. Huang et al [41] utilized a file copy technique to construct multi data counterparts and stored them in an idle device block.…”