Homework 6

22C:116, Fall 2001

Due Friday Oct 5, 2001, in class

Douglas W. Jones

Always, on every assignment, please write your name legibly as it appears on your University ID and on the class list!

  1. Problems from the text:
    a) Do problem 2 on page 373.
    b) Do problem 5 on page 374.
    c) Do problem 8 on page 374.
    d) Do problem 19 on page 375.
    e) Do problem 25 on page 376.

  2. Background: The 4-terabyte RAID used as the primary disk subsystem on each enterprise server (mainframe) at the John Deere computer center in Moline Iowa used a total of 11 terabytes of disk drives to implement the 4 terabytes seen by the user.

    Part a) From this information, what can you conclude about the RAID organization. See The discussion on pages 302 through 306 and try to fit this RAID into the models given there. What are the extra 7 terabytes used for? Hint: Your answer must, of necessity, be speculative!

    Part b) Where does the disk scheduling function fit in a system that uses RAID technology? Does this follow from the statement "a RAID should look like a SLED to the operating system, but have better performance ..." (page 303). If not, why not?