• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

J4 ›› 2011, Vol. 33 ›› Issue (1): 66-69.doi: 10.3969/j.issn.1007130X.2011.

• 论文 • 上一篇    下一篇

碎片影响闪存性能分析与改进

张翔立,翟建东   

  1. (华中科技大学信息与系统技术研究所,湖北 武汉 430074)
  • 收稿日期:2010-01-28 修回日期:2010-05-13 出版日期:2011-01-25 发布日期:2011-01-25
  • 通讯作者: 张翔立 E-mail:zxl@whty.com.cn
  • 作者简介:张翔立(1955),男,湖南长沙人,硕士,副教授,研究方向为计算机信息与系统。翟建东(1984),男,河北衡水人,硕士,研究方向为闪存存储与信息安全。

Performance Analysis and Improvement   of Flash Under Fragmentations

ZHANG Xiangli,ZHAI Jiandong   

  1. (Institute of Information and System Technology,
    Huazhong University of Science and Technology,Wuhan 430074,China)
  • Received:2010-01-28 Revised:2010-05-13 Online:2011-01-25 Published:2011-01-25

摘要:

闪存中不存在机械装置,因此碎片对闪存性能产生影响的原因不是由于寻找时间的增加,而是由闪存自身的特点所造成的。通过引入FTL,使得现有的文件系统可以直接应用到闪存,但FTL也是引起碎片对闪存性能影响的原因。本文对基于日志的FTL进行分析,当闪存中存在碎片时,FTL合并方式的不同引起了闪存性能的下降,根据此原因提出填补间隔的改进方案,并论证了此方案的有效性。

关键词: 闪存, 闪存转换层, 碎片, 合并

Abstract:

Unlike a hard disk, there is no mechanical parts in flash. Therefore, the reason of disk fragmentation weakening the performance of the flash is not seekdelay, but is its own characteristics. Through inducting the Flash Translation Layer(FTL), the existing file system can directly be applied to the flash. At the same time, FTL is the reason of performance degradation of flash under  fragmentations. When there is some fragmentations in flash, the difference of merge operation types result in the performance degradation. On the basicis of  reason analysis,a scheme of padding the spacing is put forward and its validity is demonstrated.

Key words: NAND flash;flash translation layer;disk fragmentation;merge