A Framework to Evaluate RAID Dual Controller Reliability and Performance

The costs of data loss and unavailability can be large, so businesses use many data protection techniques, such as remote mirroring, snapshot and RAID, to guard against failures. RAID dual controller technology makes data more accessible by preventing downtime due to a single point of failure with a single RAID controller, a dual controller model was devised to avoid data loss or even data corruption. Evaluations of the storage system dependability have focused mainly on disk arrays, including the dependability of array hardware and RAID mechanisms and the recovery time after failure. We use modeling technology, including failure tree theory and stochastic Petri nets, to evaluate the dependability and the performance of dual controller system. The results show that, in addition to improving the reliability, dual controller design can improve the average utilization rate of string controller by selecting the channel transfer rate and the communication means between the array controller and the string controller properly.