Abstract
This article investigates the application of minimal-total-processing-time (MTPT) scheduling disciplines to rotating storage units when random arrival of requests is allowed. Fixed-head drum and moving-head disk storage units are considered, and emphasis is placed on the relative merits of the MTPT scheduling discipline with respect to the shortest-latency-time-first (SLTF) scheduling discipline. The results of the simulation studies presented show that neither scheduling discipline is unconditionally superior to the other. For most fixed-head drum applications, the SLTF discipline is preferable to MTPT, but for intra-cylinder disk scheduling the MTPT discipline offers a distinct advantage over the SLTF discipline. The computational requirements of an algorithm that implements the MTPT scheduling discipline are shown to be comparable to SLTF algorithms. In both cases, the sorting procedure is the most time-consuming phase of the algorithm.
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Index Terms
- Minimal-total-processing time drum and disk scheduling disciplines
Recommendations
On the near-optimality of the shortest-latency-time-first drum scheduling discipline
For computer systems in which it is practical to determine the instantaneous drum position, a popular discipline for determining the sequence in which the records are to be accessed is the so-called shortest-latency-time-first, SLTF, discipline. When a ...
Summary of minimal-total-processing-time drum and disk scheduling disciplines
SOSP '73: Proceedings of the fourth ACM symposium on Operating system principlesThis article investigates the application of minimal-total-processing-time (MTPT) scheduling disciplines to rotating storage units when random arrival of requests is allowed. Fixed-head drum and moving-head disk storage units are considered and ...
Summary of minimal-total-processing-time drum and disk scheduling disciplines
This article investigates the application of minimal-total-processing-time (MTPT) scheduling disciplines to rotating storage units when random arrival of requests is allowed. Fixed-head drum and moving-head disk storage units are considered and ...
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