Architecture And Data Layout Of Network Based Disk Arrays

Redundant disk arrays are a popular method to improve the reliability and performance of disk storage and an ever-increasing number of array architectures and data layouts are being proposed to balance cost, performance, and reliability. In recent years, along with the rapid pace of secondary storage technology and network technology, network storage has become more and more common. Unfortunately, there are few researches on architecture and data layout of network based disk arrays.This dissertation discusses data layout technology for improving reliability and scalability in network based disk arrays. Two parity declustering data layouts for network based disk arrays are proposed in this dissertation."Weighted parity declustering data layout"distinguishes local/remote disk access performance when use parity declustering technology in network RAID. It improves degraded- and reconstruction-mode performance and reliability greatly."String parity declustering data layout"can tolerate single string (node) failure in network RAID, the reliability of this data layout is several order of magnitudes better than those of other data layouts.This dissertation also studies double-erasure-correcting codes and double-erasure data layouts. A new double-erasure data layout method is proposed in this dissertation. The double-erasure data layouts produced by this method have better check disk overhead than those produced by other methods.Finally, RAID expansion is discussed in this dissertation, and a faster RAID expansion method is proposed as well. The expansion performance of this method is several order of magnitudes better than that of the simple method. The performance of data layouts that is produced by this method is compared that of data layout produced by the simple method.