| Abstract |
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Storage system designers prefer to limit the maximum
queue length at individual disks to only a few outstanding
requests, to avoid possible request starvation. In this paper,
we evaluate the benefits and performance implications
of allowing disks to queue more requests. We show that the
average response time in the storage subsystem is reduced
when queuing more requests and optimizing (based on seek
and/or position time) request scheduling at the disk. We argue
that the disk, as the only service center in a storage subsystem,
is able to best utilize its resources via scheduling
when it has the most complete view of the load it is about
to process. The benefits of longer queues at the disks are
even more obvious when the system operates under transient
overload conditions.
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 Additional Information
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Index Terms- disk scheduling, unfair scheduling, response
time distribution, request starvation
Citation:
Alma Riska, Erik Riedel,
"It’s not fair - evaluating efficient disk scheduling,"
mascots,
p. 288,
11th IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunications Systems (MASCOTS'03),
2003
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