华南理工大学学报(自然科学版) ›› 2007, Vol. 35 ›› Issue (5): 75-80.

• 计算机科学与技术 • 上一篇    下一篇

磁带库随机I/O 缓冲调度算法的性能

吴涛 杨捷   

  1. 华南理工大学 计算机科学与技术学院,广东 广州 510640
  • 收稿日期:2006-03-14 出版日期:2007-05-25 发布日期:2007-05-25
  • 通信作者: 吴涛(1975-),男,博士,讲师,主要从事网络与信息存储方面的研究. E-mail:ssewt@scut.edu.cn
  • 作者简介:吴涛(1975-),男,博士,讲师,主要从事网络与信息存储方面的研究.

Random I/O Performance of Buffer Scheduling Algorithm for Tape Library

Wu tao  Yang Jie   

  1. School of Computer Science and Engineering, South China Univ. of Tech. , Guangzhou 510640 , Guangdong , China
  • Received:2006-03-14 Online:2007-05-25 Published:2007-05-25
  • Contact: 吴涛(1975-),男,博士,讲师,主要从事网络与信息存储方面的研究. E-mail:ssewt@scut.edu.cn
  • About author:吴涛(1975-),男,博士,讲师,主要从事网络与信息存储方面的研究.

摘要: 为了提高磁带设备的在线存储效率,提出了一种磁带库缓冲调度算法.该算法采用磁盘驱动器做援存,将磁带库设备虚拟为逻辑块设备使用.同时,提出了主动写回以及读预取方法,将磁带库的随机读写操作顺序化,以改善系统随机读写性能.文中还对算法性能进行了详细分析,并利用仿真方法对算法进行了测试,结果证明系统集合I/O 和单I/O响应时间能够得到明显改善.

关键词: 磁带存储, 虚拟存储, 缓冲调度, 主动写回, 数据预取

Abstract:

In order to improve the on-line storage efficiency of magnetic tape , a buffer scheduling algorithm for tape library is put forward , in which the medium changer is virtualized as a logical block device and the disk drive is used as a buffer. An active write-back method and a data prefetching strategy are then presented to manage the random I/O process orderly and to improve the random I/O performance. Besides , the performance of the algorithm is ana-lyzed in detail and a simulation is performed to test the algorithm. The results demonstrate that the proposed algorithm greatly deduces the aggregate and single I/O response time.

Key words: magnetic tape storage, virtual storage, buffer scheduling, active write-back, data prefetching