DACO: A High-Performance Disk Architecture Designed Specially for Large-Scale Erasure-Coded Storage Systems
DACO: A High-Performance Disk Architecture Designed Specially for Large-Scale Erasure-Coded Storage Systems
复制标题
DOI：
10.1109/tc.2010.22
复制
发表时间：
2010-10
影响因子：
3.7
通讯作者：
Mingqiang Li;J. Shu
中科院分区：
文献类型：
--
作者：
Mingqiang Li;J. Shu
大规模擦除编码存储系统在进行小写操作时，由于读-修改-写操作导致的I/O拥塞和磁盘介质访问拥塞，导致了严重的性能问题。所有现有的基于传统磁盘的技术都只能提供非常有限的性能改进。本文提出了一种新的具有复合操作的磁盘体系结构（DACO），其磁盘介质访问接口由三种操作组成：读、写和复合操作（CO）。CO采用基于扇区的流水线技术实现块级数据修改操作，可以代替小写操作中的读-修改-写操作。在具有t容错性的大规模擦除编码存储系统中采用DACO时，每个小写操作可以分别减少t个I/ o和t个磁盘介质访问操作。这在本质上减轻了I/O拥塞和磁盘媒体访问拥塞，因此可以显著提高大规模擦除编码存储系统的性能。一项模拟研究表明，DACO可以提供显著的性能改进：即使在t=1的最坏情况下，平均I/O响应时间也最多减少31.16%。本文还讨论了DACO的重要实施问题，并对DACO所涉及的额外成本进行了调查。
Large-scale erasure-coded storage systems have a serious performance problem due to I/O congestion and disk media access congestion caused by read-modify-write operations involved in small-write operations. All the existing technologies based on the conventional disk can provide very limited performance improvement. This paper presents a new Disk Architecture with Composite Operation (DACO), whose disk media access interface consists of three kinds of operations: READ, WRITE, and Composite Operation (CO). The CO adopts a sector-based pipeline technology to implement block-level data modify operations, and thus, can replace the read-modify-write operations involved in small-write operations. When the DACO is adopted in a large-scale erasure-coded storage system with t fault tolerance, t I/Os and t disk media access operations can be reduced in each small-write operation, respectively. This alleviates both I/O congestion and disk media access congestion in nature, and thus, can remarkably improve the performance of large-scale erasure-coded storage systems. A simulation study shows that the DACO can provide significant performance improvement: reducing the average I/O response time by up to 31.16 percent even in the worst case where t=1. This paper also discusses the important implementation issues of the DACO and investigates the additional cost involved in the DACO.