Shiao-Li Tsao and Yueh-Min Huang
Department of Engineering Science
National Cheng-Kung University
Tainan, Taiwan, R.O.C.
Studies on video servers have focused on improving the throughput of storage devices and the real-time retrieval and delivery of large amounts of video data. Previous studies on the improvement of disk throughput mainly focused on reducing the overhead of disk seeking in order to obtained higher disk throughput. However, these studies did not consider the actual characteristics of hard disks. Recently, the zoning technique has been applied to increase disk capacity. The significant effect of disk zoning is that the data transfer rates (bandwidths) increase from the outermost to the innermost zones. In this study, we present a novel data placement scheme with various block sizes on different regions of a hard disk. In our scheme, we can not only reduce the seek time overhead, but also use the advantages of various bandwidths from a disk to achieve higher throughput. Compared with previous studies, our proposed scheme can improve disk throughput significantly, which can support more users with the same buffer requirement.
Keywords: video-no-demand, video server, data placement, disk zoning, storage system
Received Febuary 29, 1996; revised May 21, 1997.
Communicated by Ming-Tat Ko.