• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

J4 ›› 2010, Vol. 32 ›› Issue (9): 107-110.doi: 10.3969/j.issn.1007130X.2010.

• 论文 • 上一篇    下一篇

ZFS文件系统中双容错编码性能的研究

张斌,眭聚磊,童健聪,王刚,刘晓光   

  1. (南开大学信息技术科学学院, 天津 300071)
  • 收稿日期:2010-03-13 修回日期:2010-06-15 出版日期:2010-09-02 发布日期:2010-09-02
  • 作者简介:张斌(1987),男,天津人,研究方向为网络存储;眭聚磊,硕士,研究方向为分布式存储;童健聪,硕士,研究方向为分布式存储与并行计算;王刚,博士,教授,研究方向为海量信息存储、并行与分布式计算;刘晓光,博士,副教授,研究方向为并行与分布式计算、计算智能、计算经济学。
  • 基金资助:

    国家863计划资助项目(2008AA01Z401);国家自然科学基金资助项目(60903028);教育部博士点基金课题(20070055054);天津市科技发展计划课题(08JCYBJC13000)

Evaluating the Encoding Performance of  the Double FaultTolerant Codes in ZFS

ZHANG Bin,SUI Julei,TONG Jiancong,WANG Gang,LIU Xiaoguang   

  1. (School of Information Technical Science,Nankai University,Tianjin 300071,China)
  • Received:2010-03-13 Revised:2010-06-15 Online:2010-09-02 Published:2010-09-02

摘要:

ZFS是Sun推出的一款革新性的文件系统,它支持用户构建镜像以及单容错/双容错的软Raid。其双容错编码方案采用的是ReedSolomon编码(RS码)。由于RS码是基于有限域运算,编码/解码时间复杂性差是其根本性的缺陷。ZFS对写操作的处理采用的是聚合后追加的方式而非传统的覆盖方式,每次写操作都会进行一次编码计算。因此,编码计算性能是影响文件系统整体性能的重要因素之一。本文的工作是将RDP这一基于奇偶校验的双容错编码与ZFS相结合,替代ReedSolomon编码,以优化文件系统写操作的性能。我们设计了Cache优化的RDP编码算法,在ZFS中进行了实现,并通过实验验证了这一方法的有效性。

关键词: ZFS, 容错编码, RDP

Abstract:

ZFS is an innovative file system invented by Sun, on which a user can construct mirror, single faulttolerant or double faulttolerant soft Raid systems. Its doubleerasure code is the ReedSolomon (RS) code. RS code based on calculating in the Galois field has a high time complexity. ZFS uses an appending writing strategy after the writing request aggregation instead of the traditional overwriting strategy. The performance of coding is one of the most important factors for ZFS, because coding calculation is necessary during every write operation. An approach to improving the writing performance by combining between ZFS and the RDP code whose computation is based on exclusiveor, instead of RS code, is shown. We have designed and implemented an algorithm by using cache’s feature to improve the RDP coding performance in ZFS. Finally, the experiments have validated this approach.

Key words: ZFS;faulttolerant coding;RDP