CS439: Principles of Computer Systems
Homework 8, Part 1
Due: 9:45a Thursday, October 29, 2015 Part 1 of the
homeworks must be submitted electronically. Please refer to the
homework turnin instructions.
Question 9.19, page 852 in the Second Edition, page 880 in the Third Edition, B&O.
Disk requests come into the disk driver for tracks 10, 22, 20, 2, 40,
6, and 38, in that order. A seek takes 6 msec per track moved. How
much seek time is needed for the following scheduling algorithms?
c) LOOK (SCAN, but doesn't move to the end)
In all cases, the arm is initially at track 20, and you may assume
that the head is traveling towards higher numbers.
from Tannenbaum Chapter 5 Number 24.
Suppose I have a disk such as the 320GB SATA drive
described here and I have a workload
consisting of 10,000 reads to sectors randomly scattered across the
disk. How long will these 10,000 request take (total) assuming the
disk services requests in FIFO order?
Some file allocation schemes limit the size of the file whether or not
there is enough space for a larger file. Which ones and why?
- Multi-Level index
How does a journaling file system maintain file system consistency
even in the event of a crash? Name an example of a journaling file