Performance analysis of RAID for different communication mechanism between RAID controller and string controllers

A Stochastic Petri Nets (SPN) model of the orthogonal RAID is constructed. After analyzing the performance of the system we can see that the performance of the system has the relationship with the choice of communication mechanism, which is the polling mechanism or interrupt mechanism, between the RAID controller and the string controllers. The faster the rate of the "Go to Communication" transition in the SPN, the higher the average utilization of the string controller, and the better the performance of RAID. The rate is larger under the polling mechanism than that under the interrupt mechanism in RAID. Thus, the polling mechanism between the RAID controller and the string controllers should be adopted to improve the performance of RAID.