I/O buffer performance in a virtual memory system

Abstract

In this study we construct a simulator of a data base management system running in a virtual memory environment. We use the simulator to investigate the value of using an I/O buffer in this environment. The simulator is driven by trace data obtained with a software probe. The simulator is validated and is used to verify a theoretical model which predicts paging and disk access rates produced by use of an I/O buffer in a virtual memory environment. Results from a multi-factor set of simulation experiments are analyzed. The factors include three page replacement algorithms, four buffer management algorithms, five virtual buffer sizes, three values for real memory and six well known and widely differing distributions for creating sequences of requests to the simulated data base management system.