A mathematical hard disk timing model for full system simulation

Benjamin S Parsons, Purdue University

Abstract

This work introduces a mathematical hard disk timing model and validates it by implementing it in an execution-driven full-system simulator. While very accurate disk simulators exist, their complexity is often not warranted when disk simulation is not the primary focus. This model depends far less on details of the disk structure or the physical layout of the disk, making it less complex and easier to configure. By introducing novel ways of mathematically and probabilistically modeling the disk layout and reorder queues, the need for a physical model of the disk platter is eliminated. Current full-system simulators do not include a realistic disk timing model, giving them large and variable errors compared to real systems when modeling disk-intensive workloads. With this model it is shown that disk-intensive full system simulation can be accurate, with benchmarks averaging 12% error compared to a real system. This model will benefit full-system performance simulations by bridging the gap between complex and highly-specific disk simulators and the actual performance modeling requirements needed for effective use of full-system simulators.

Degree

M.S.E.C.E.

Advisors

Pai, Purdue University.

Subject Area

Computer Engineering

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