Reducing Disk I/O Performance Sensitivity for Large Numbers of Sequential Streams

Retrieving sequential rich media content from modern commodity disks is a challenging task. As disk capacity increases, there is a need to increase the number of streams that are allocated to each disk. However, when multiple streams are accessing a single disk, throughput is dramatically reduced because of disk head seek overhead, resulting in requirements for more disks. Thus, there is a tradeoff between how many streams should be allowed to access a disk and the total throughput that can be achieved. In this work we examine this tradeoff and provide an understanding of issues along with a practical solution. We use Disksim, a detailed architectural simulator, to examine several aspects of a modern I/O subsystem and we show the effect of various disk parameters on system performance under multiple sequential streams. Then, we propose a solution that dynamically adjusts I/O request streams, based on host and I/O subsystem parameters. We implement our approach in a real system and per...

• Type: Conference
• Year: 2009
• Where: ICDCS
• Authors: George Panagiotakis, Michail Flouris, Angelos Bilas
• Keywords: Computer Science, I/O Request Streams, I/O Streams, ICDCS 2009, Multiple Sequential Streams