Journal of South China University of Technology (Natural Science Edition) ›› 2007, Vol. 35 ›› Issue (5): 75-80.

• Computer Science & Technology • Previous Articles     Next Articles

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.

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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