Extracting the performance characteristics of the different I/O configurations of the I/O system.
These activities are independent. The characterization of application is done off-line and the application I/O model can be applied to analyze different target systems. The application I/O model is defined by three characteristics: metadata, spatial global pattern and temporal global pattern. The I/O model of the application is expressed by I/O phases, where an I/O phase is a repetitive sequence of same pattern on a file for a number of processes of the parallel application. A phase will be significant depending on data transferred that represent its weight.