PYTHIA AND PYTHIA WK - TOOLS FOR THE PERFORMANCE ANALYSIS OF MASS-STORAGE SYSTEMS/

The constant growth on the demands imposed on hierarchical mass storag e systems creates a need for frequent reconfiguration and upgrading to ensure that the response times and other performance metrics are with in the desired service levels, This paper describes the design and ope ration of two tools, Pythia and Pythia/WK, that assist system managers and integrators in making cost-effective procurement decisions, Pythi a automatically buids and solves an analytic model of a mass storage s ystem based on a graphical description of the architecture of the syst em, and on a description of the workload imposed on the system, The us e of a modeling wizard to perform this conversion from a graphical des cription of a mass storage system to an analytic model makes Pythia un ique among analytic performance tools, Pythia/WK uses clustering algor ithms to characterize the workload from the log files of the mass stor age system, The resulting workload characterization is used as input t o Pythia. (C) 1997 by John Whey & Sons, Ltd.