Disk scheduling for variable-rate data streams

Abstract

We describe three disk scheduling algorithms that can be used in a multimedia server for sustaining a number of heterogeneous variable-rate data streams. A data stream is supported by repeatedly fetching a block of data from the storage device and storing it in a corresponding buffer. For each of the disk scheduling algorithms we give necessary and sufficient conditions for avoiding under- and overflow of the buffers. In addition, the algorithms are compared with respect to buffer requirements as well as average response times.