Disk throughput estimation

• Authors: David L. Stone;Rollins Turner
• Venue: ACM '72 Proceedings of the ACM annual conference - Volume 2
• Year: 1972

This is a report of practical, quantitative techniques for predicting throughput of movable head disks in a time-shared, multiprogrammed system. Theoretical relationships between throughput and load are considered first. Then a technique is explained whereby the actual source code of the timesharing monitor's disk service routine is incorporated into a simulation program. Finally, actual throughput measurements, made on a system running with carefully controlled loads, are reported. Comparisons are drawn between the results of the theory, simulation, and actual measurements. In each case, it is found that throughput increases significantly as more disk drives are added. Throughput also increases somewhat as more users ask for service.