ISSN 1000-1239 CN 11-1777/TP

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Flash存储技术

郑文静1 李明强1 舒继武1,2   

  1. 1(清华大学计算机科学与技术系 北京 100084) 2(清华大学信息科学与技术国家实验室(筹) 北京 100084) (zhengwj07@mails.tsinghua.edu.cn)
  • 出版日期: 2010-04-15

Flash Storage Technology

Zheng Wenjing1, Li Mingqiang1, and Shu Jiwu1,2   

  1. 1(Department of Computer Science and Technology, Tsinghua University, Beijing 100084) 2(Tsinghua National Laboratory for Information Science and Technology, Beijing 100084)
  • Online: 2010-04-15

摘要: Flash存储器具有非易失性、固态性、体积小、重量轻、抗震动、高性能、低能耗等特点.近年来,随着容量的提高和价格的降低,Flash存储器在通用计算环境中的应用技术迅速成为研究热点.研究的目的是对Flash存储技术研究现状进行分析、总结,以期为进一步的研究工作提供启发.首先介绍了Flash的存储特性,探讨了其在存储体系结构中地位,并讨论了管理Flash存储器的两种软件体系结构.然后重点分析、总结了Flash存储的各项关键技术的研究现状,包括地址映射机制、垃圾回收机制、磨损均衡策略、基于Flash的buffer cache管理策略、基于Flash的索引数据结构以及基于Flash的事务处理技术.最后对Flash存储技术的研究现状进行总结,提出可能的未来研究方向.

关键词: 闪存, 存储管理, 闪存转换层, 缓存, 索引数据结构, 事务处理, 垃圾回收

Abstract: Flash memory has the merits of non-volatility, solid-stateness, small volume, light weight, shock resistance, high sequential access performance, high random read performance and low power consumption. Though flash memory has been widely applied in embedded systems and various kinds of technologies have been proposed in this area, recently, with the continual increase in capacity and decrease in cost, there are strong motives from both industrial and academic world to apply flash memory in notebook computers and enterprise storage systems, which raise new challenges for building a high performance, high reliable and low power-consuming storage system based on flash memory. In this paper, a comprehensive analysis and summary of the state of the art of technologies that are related to flash memory are given in the hope of enlightening future work. First, an introduction to the characteristics of flash memory and a discussion on the role of flash memory in storage system architecture are presented. Then, several key techniques for efficient exploitation of flash memory are reviewed in detail, including address-mapping technique, garbage collection mechanism, wear-leveling strategy, flash-aware buffer cache replacement strategy, flash-aware indexing data structure and flash-based transaction technique. Finally, a panoramic view is provided and possible future research areas are given.

Key words: flash, storage management, flash translation layer, buffer cache, indexing data structure, transaction, garbage collection