An Anomaly in Disk Scheduling: A Comparison of FCFS and SSTF Seek Scheduling Using an Empirical Model for Disk Accesses A model for disk accesses based on published measurements is developed. The model is used to show that under highly probable conditions, FCFS seek scheduling is superior to SSTF scheduling in the sense of having a lower mean queue length. A simple example of an arrival sequence illustration this anomaly is presented. CACM January, 1976 Wilhelm, N. C. disks, disk scheduling, seek scheduling 3.72 4.35 4.41 4.6 6.35 CA760102 JB January 5, 1978 10:42 AM 2628 4 2891 2891 4 2891 2891 4 2891 3072 4 2891 2375 5 2891 2628 5 2891 2891 5 2891 2891 5 2891 2891 5 2891 3153 5 2891 2741 6 2891 2891 6 2891