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

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