Previous studies have already established the superiority of disk scheduling algorithms based on
total access time over those that are based only on seek time. The most straightforward
algorithm in this class of scheduling policy is oftentimes known as the Shortest Access Time First
(SATF) algorithm. However, all previous studies on SATF scheduling use a disk drive model in
which the seek time is precisely known and without variation. In practice, due to a number of
reasons, there is always some deviation in seek time from its nominal specification. This
variation can be problematic for the SATF algorithm. The purpose of this paper is to investigate
the effect of seek time variability on the behavior of SATF algorithm, and explore ways for
optimizing its peformance under this real world condition.
By: Spencer Ng
Published in: RJ10206 in 2001
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