A High-Performance and High-Reliability RAIS5 Storage Architecture with Adaptive Stripe.

In the era of big data, the traditional RAID storage system has been incapable of meeting the requirements of performance and reliability for the large amount of data storage and computing. In view of the situation, Solid State Disks (SSDs), which can provide better performance than Hard Disk Drives (HDDs), are widely used to construct storage arrays in enterprise environments. Today many studies on Redundant Array of Independent SSDs (RAIS) storage systems concentrate more on improving write performance, and show less attention on the reconstruction performance of RAIS storage systems. In this paper, we proposed RAIS5AS, a novel RAIS5 storage architecture with adaptive stripe for improving the performance and reliability of RAIS5. RAIS5AS distinguishes between logical stripe and physical stripe. Logical stripe is a traditional RAID stripe. Physical stripe consists of the blocks (in a logical stripe) which have been written data. When handling write requests, RAIS5AS uses physical stripe as the basic processing unit to choose which blocks are read to compute the new parity block. When recovering data, RAIS5AS skips the unused failed blocks. In addition, RAIS5AS simplifies the synchronization process of RAIS5 storage system. We have implemented the proposed scheme and carried out a series of experiments. RAIS5AS on average improves write performance and reconstruction performance of the basic RAIS5 by up to 7.92% and 95.65% respectively, and those of JOR by 9.16% and 14.57% respectively.