Design and evaluation of disk scheduling policies for high-demand multimedia servers

We propose and evaluate techniques to manage disk storage systems for multimedia document servers with constrained I/O resources. We also evaluate the requirements for the main memory to maintain desired levels of quality of presentation (QoP) for multiple users. This is achieved by attempting to minimize the number of tardy frames in end-to-end delivery of multimedia data. Inter-media and intra-media temporal synchronization at the user-interaction level are essential concerns for multimedia servers. Scheduling of multimedia frames has direct impact on both intra-stream and inter-stream multimedia synchronization. In order to effect such synchronization, we propose several O(n log n+mn) heuristics to schedule multimedia frames between the disks and destination memories of the multimedia systems, where m is the number of logical I/O channels and n is the number of frames of multimedia data. We study the performance of these heuristics via simulations and show the tradeoffs between the system resources and QoP parameters.