Adaptive disk striping for parallel input/output

As disk capacities continue to rise more rapidly than transfer rates, adaptive, redundant striping smoothly trades capacity for higher performance. We devel-oped a fuzzy logic rule base for adaptive, redundant striping of les across multiple disks. This rule base is based on a queuing model of disk contention that includes le request sizes and disk hardware parame-ters. At low loads, the rule base stripes aggressively to minimize response time. As loads rise, it stripes less aggressively to maximize aggregate throughput. This adaptive striping rule base is incorporated into our second generation Portable Parallel File Sys-tem (PPFS II). Experimental results showed that the analytical models of disk striping are capable of accurately predicting le system behavior. Also, it is shown that, depending on the access pattern, adaptive striping can double the input/output per-formance compared to striping with xed distribution parameters.