A Data Layout Method in Heterogeneous RAID

The data layout of traditional RAID can´t adapt to the heterogeneous RAID that consists of disks with different capacity and/or performance, because it will cause waste of disk storage space and decrease of the integrated disks´ bandwidth. Based on the concept of ldquostripe patternrdquo, we bring out the concept of ldquopseudo stripe patternrdquo and propose to place data in heterogeneous RAID with repetitions of pseudo stripe pattern. It takes into account of storage space and array I/O bandwidth, while promising acceptable data management overhead. The results of simulations validate that heterogeneous RAID applying our data layout policy exhibits better and steadier performance compared with that applying traditional homogeneous RAID data placement.