A disk model with dual read/write heads is proposed to improve disk system performance. Dual head disk model can reduce the average seek distance either by selecting the closer of the two heads or by dividing the disk surface into two separated regions, one for each head. And also, because the reduced seek time can decrease any queuing delay, disk I/O response time can be reduced significantly. To compare the performance of the dual head disk model with the conventional disk model, a disk simulator in which four disk scheduling algorithms are implemented is developed. Both synthetically generated random workload and two other workloads constructed by accessing patterns traced are used for performance evaluation. Simulation results show that a higher performance by the proposed disk system as compared to the conventional disk system can be obtained under both light and heavy workloads. The dual head disk model can give better performance in the application environment that has a relatively high seek time ratio.
All Science Journal Classification (ASJC) codes
- Hardware and Architecture