One can uncover the chunk size with the following code. The basic idea is to perform reads
Question:
Figure 6.27 Results from running the chunk size algorithm of Shear on a mock storage system.
If you run this code and plot the measured time as a function of c, then you will see that the measured time is lowest when the requestA and requestB reads fall on two different disks. Thus, the values of c with low times correspond to the chunk boundaries between disks of the RAID.
a. Figure 6.27 shows the results of running the chunk size algorithm on an unknown RAID system.
¢ What is the chunk size of this storage system?
¢ What do the measured times of 0.75 and 1.5 seconds correspond to in this storage system?
b. Draw the graph that would result from running this Shear code on a storage system with the following characteristics:
Number of requests: N = 1000
¢ Time for a random read on disk: 5 ms
¢ RAID level: RAID 0
¢ Number of disks: 8
¢ Chunk size: 12 KB
Step by Step Answer:
Computer Architecture A Quantitative Approach
ISBN: 978-0123704900
4th edition
Authors: John L. Hennessy, David A. Patterson