Advance Operating Systems Questions

CS 5500 Advanced Operating Systems

Homework #5

Please refer to the syllabus for expectations of homework professionalism

and appearance. Your homework is expected to be an individual effort. It is

also expected to be neat and clearly organized. The University provides

access to many software applications. Use them. Hand written papers and

poorly drawn diagrams are not acceptable. You must submit the softcopy of

your homework in a Word file by the specified due date and time. You can

find the submission link in the Blackboard.

This homework is due: June 23, 2020, 09:00 AM

Total points: 16

The cover page of your homework will contain only the following

information in the format given below:

Name:

Class ID:

E-mail:

Course #: CS 5500

Homework #: Homework 5

Semester: Summer 2020

1. [2 pts] Explain the benefits of Copy on Write (CoW).

2. [2 pts] Explain the sequence of events that happens when a page-fault occurs.

3. [6 pts] Consider the following page reference string:

1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6.

How many page faults would occur for the following replacement algorithms, assuming

one, two, three, four, five, six, or seven frames? Remember all frames are initially empty,

so your first unique pages will all cost one fault each.

a. FIFO replacement

b. LRU replacement

c. Optimal replacement

4. [6 pts] Explain the differences between the following disk scheduling algorithms. Show

the scheduling sequence of each disk scheduling algorithm for the following queue:

Queue = 181, 39, 93, 129, 14, 124, 157, 59, 62

Head starts at 127

a. FCFS and SSTF

b. SCAN and LOOK

c. LOOK and C-LOOK