Data I/O Optimization in Storage Systems

Abstract. One of the most effective ways to improve the I/O perfor-mance of a storage system is to enhance the hard disk’s read/write ability. We used an I/O processing node in the storage network to optimize data organization and I/O performance. By analyzing existing algorithms and different requirements for read and write operations, we designed an im-proved optimizing algorithm to schedule disk I/O requests. It selects the closest request in queue to process first, and uses an EW mechanism to modify write locations. Typically, the algorithm can reduce a disk’s average response time by about 15%-17%. This paper also presents an EW stripe and copy algorithm that can improve I/O performance using parallel disk accesses, and enhance reliability by data duplication. With one copy preserved, it can reduce the response time by about 30%.