Video File Allocation over Disk Arrays for Video-On-Demand

Yuewei Wang, Jonathan C.L. Liu, David H.C. Du1 and Jenwei Hsieh Distributed Multimedia Research Center2 & Department of Computer Science, University of Minnesota fywang,cliu,du,[email protected] Abstract A Video-on-Demand (VOD) server needs to store hundreds of movie titles and to support thousands of concurrent accesses. We de ne access pro le as the number of concurrent accesses to each movie title that should be supported by a VOD server. A current highend magnetic disk array (disk) can only support tens of MPEG-2 concurrent accesses, and it is necessary to replicate and/or stripe the hot movie les over multiple disk arrays. How to replicate, stripe, and place the movie les over a minimum number of magnetic disk arrays such that a given access pro le can be supported is an important problem. In this paper, we formulate and solve this problem. The result of this study can be applied to the design of the storage subsystem of a VOD server to economically minimize the cost or to maximize the utilization of disk arrays.