Impact of Extra Space on Striping

Figure 1(c) shows how the components of the average read cost respond to different degree of striping ($D_s$) under a random read workload. (In this case, $D_d = D_m = 1$.) By restricting the disk head within a small seek distance, striping lowers seek delay. Unlike mirroring, it has no impact on rotational delay. As $D_s$ increases, rotational delay dominates if striping is the only technique employed.