operating system

Deadline: Saturday 08/12/2018 @ 23:59

[Total Mark for this Assignment is 6]

Operating Systems

IT-241

College of Computing and Informatics

Question One

1.5 Mark

Learning Outcome(s):

Describe the OS mechanism for process management, timing, memory, I/O, file and concurrency management.

1. What are the three reasons that buffering is performed?

Question Two

1.5 Mark

Learning Outcome(s):

Describe the OS mechanism for process management, timing, memory, I/O, file and concurrency management.

What is the least privilege principle? Why such a principle aid in the creation of protection systems?

Question Three

2 Mark

Learning Outcome(s):

Describe the OS mechanism for process management, timing, memory, I/O, file and concurrency management

Consider the following request queue for disk cylinders:

75, 168, 92, 22, 55, 78, 39, 82, 157, 99

Using following disk scheduling algorithms, find the total head movements using schematic diagram for a disk of 200 cylinders (0-199). It is assumed that read write head is initially present at cylinder number 50.

a. First Come First Serve (FCFS)

b. Shortest Seek Time First (SSTF)

Question Four

1 Mark

Learning Outcome(s):

Describe the OS mechanism for process management, timing, memory, I/O, file and concurrency management

Why is DMA used for devices that execute large transfers?