A Framework for the Storage and Retrieval of Continous Media Data

Continuous media applications require a guaranteed transfer rate of data which conventional storage servers are not designed to provide The aim of this paper is to provide a general framework for the de sign of storage servers that deal with both continuous and non continuous media data We present several algorithms for the concurrent transfer of continuous media data for multiple requests with di erent rates The algorithms provide high throughput by reducing the seek latency time and by eliminating rotational la tency incurred when accessing data on disks Each of these algorithms is accompanied by an admission control scheme to restrict the number of concurrent requests being serviced at any given time We also augment these algorithms to support conventional data accesses without violating the rate guarantees of con tinuous media data requests Finally we extend our algorithms to deal with the newer disks where transfer rates vary from one track to another The algorithms presented in this paper are used in Fellini a storage server for continuous and conventional data being im plemented at AT T Bell Laboratories