Markov model prediction of I/O requests for scientific applications

Given the increasing performance disparity between processors and storage devices, exploiting knowledge of spatial and temporal I/O requests is critical to achieving high performance, particularly on parallel systems. Although perfect foreknowledge of I/O requests is rarely possible, even estimates of request patterns can potentially yield large performance gains. This paper evaluates Markov models to represent the spatial patterns of I/O requests in scientific codes. The paper also proposes three algorithms for I/O prefetching. Evaluation using I/O traces from scientific codes shows that highly accurate prediction of spatial access patterns, resulting in reduced execution times, is possible.