FileServer and WebServer Patterns

We will start with a pattern emulating the work of the fileserver disk subsystem. First we will discuss the results in WriteBack mode:

These are the graphs showing the dependence of the controller performance on the request queue depth:

RAID0, RAID5 and RAID10 arrays prove beautifully scalable depending on the number of hard disk drives in the array even when the queue is relatively small. RAID1 and RAID 10 of 2n HDDs are always faster than a single hard drive and RAID0 of n HDDs respectively. Since FileServer pattern contains only 20% of writes, Twinstor algorithm works perfectly well.