Performance of Movable-Head Disk Storage Devices
C. C. Gotlieb, Glenn H. MacEwen · Journal of the ACM · 1973
A queueing model of movable-head disk storage systems is developed so that the performance, as measured by the mean response time, can be calculated.Queue scheduling algorithms which improve the performance are considered.Single-module disk systems are analyzed, incorporating the SCAN scheduling algorithm suggested by Denning so that comparisons with the FIFO algorithm are possible.This analysis is extended to multimodule systems whereby tables of approximate glean response values time can be calculated over system parameters describing equipment characteristics, equipment configuration, system loading, file organization, and scheduling algorithm (SCAN or FIFO).The use of such tables is discussed and the applicability of the analysis to a recently marketed disk is noted.