High performance RAID system by using dual head disk structure

An approach for designing high performance disk array systems using a dual head disk structure is presented. In general, both I/O bandwidth and reliability can be significantly improved by using disk array systems, i.e., RAID. However, the performance of RAID systems can be significantly degraded where small read/write accesses are frequently requested. Thus, the dual head disk structure is applied to improve the performance of RAID systems. The dual head disk model can reduce not only the maximum seek time but also the average seek time by dividing the disk surface into two separated regions, one for each head. To compare the performance of the dual head RAID (DH-RAID) system with the conventional RAID systems, simulations are performed with two types of RAID configurations and several workloads. Simulation results show higher performance can be obtained by DH-RAID systems as compared with the conventional RAID systems. The DH-RAID model can provide better performance in the application environment that has a relatively high seek time ratio.