RSA: RAID system with self-healing and active data migration

The reliability of the traditional RAID system can be guaranteed through the data backup and data redundant technologies. The system can utilize data recovery and reconstruction operations to recover data in case of the disk failure; however it will result in longer data recovery time and negative impact on system performances. Moreover, the possibility of secondary failure will be increased during the recovery period. This paper proposed a new RAID-based system using disk self-healing and active data migration technologies to improve the reliability of the storage system called RSA, which allocates reserved space in every disk and arranges to redirect the data in the non-repairable sectors to the reserved space, when the number of the bad sectors in the disk exceeds threshold, the system will copy data of the unreliable disk to a new one, this process, as we called active data migration can avoid lengthy data reconstruction. This technology can adjust migration speed to reduce the impact on the front end performance dynamically and prioritize user requests when the system I/O workload is bursting. The overall results indicate that the RSA storage system can improve reliability of the system with little influence.