Hierarchical Storage Systems for Interactive Video-on-demand

On-demand video servers based on hierarchical storage systems are able to o er highcapacity and low-cost video storage. In such a system, video les are stored in the tertiary level and transferred to the secondary level to be displayed. The design of video servers allowing user interaction with the playbacked video is of great interest. We have conducted a comprehensive study on the architecture and operation of such servers based on hierarchical storage systems for interactive video-on-demand. Our objective is to understand its performance characteristics, so as to design a video server to meet speci c application requirements. The applications of interest are many: distance-learning, movie-on-demand, interactive news, home-shopping, etc. The design of such a server actually involves many design choices pertaining to both architecture and operational procedures. As far as architecture is concerned, we need to consider such system parameters as bandwidth, storage capacity, and the number of