This project is finding ways to improve I/O performance by predicting future accesses based on those that have occurred in the past. The results can be applied all the way from the disk controller cache to the file system to the world wide web. It has been demonstrated that accesses to files, for example, are not random. There are patterns that can be detected and exploited. By exploiting these patterns, files can be prefetched so that the files will be present in the cache when the request occurs. Preliminary results using file system traces indicate that significant performance gains will occur. This project will (1) develop a method for tracking I/O access patterns that is efficient in terms of both space and time, (2) investigate the use of predictive cache prefetching at three levels: disk controller, file system and the world-wide web, and (3) implement a predictive cache in one or more of these areas. ***
