A system-assisted disk I/O simulation technique

Simulation and modeling are useful tools in prototyping advances in many areas of technology. The performance of modern processors is advancing much faster than that of storage components, making disk systems prime candidates for simulation. Simulating disk systems allows researchers to determine and quantify the performance impact of alternative file system designs and disk data rearrangement techniques. This paper describes SAST (System-Assisted disk I/O Simulation Technique). This technique uses a real system to estimate disk request service times, relieving the researcher from the burden of modeling the target system. The system accepts disk trace data as input, and accurately predicts disk service times. In addition, we describe a disk trace collection technique that is capable of collecting accurate trace data from the Windows 95 operating system