A hybrid simulation-queueing module for modeling UNIX I/O in performance analysis

ABSTRACT

LEXIS-NEXIS frequently develops simulation models to estimate the computer system capacity required to deliver on-line information services. The load imposed by Unix Input/Output (I/O) processes is a key factor in many of these models. However, the I/O processes themselves are seldom of interest, and explicitly modeling them results in simulations executing much slower than real time. This paper presents a hybrid simulation-queueing module that can be inserted into any simulation to accurately model I/O resource consumption and queueing delays without explicitly modeling each individual I/O process. This module is in use at LEXIS-NEXIS to day (LEXIS and NEXIS are registered trademarks of Reed-Elsevier Properties, Inc., and are used under license).

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