Operating Systems - May 2015

Electronics & Telecomm. (Semester 6)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

1 (a) What is operating system? Explain the different functions of OS. (5 marks)

1 (b) What is system call? Explain any five system calls. (5 marks)

1 (c) Describe the structure of an I-Node in UNIX. (5 marks)

1 (d) What are the different characteristics of real operating system? (5 marks)

2 (a) What is deadlock? What are the necessary and sufficient conditions to occur deadlock? Explain deadlock avoidance and Prevention. (10 marks)

2 (b) Describe process management in Linux. (10 marks)

3 (a) Explain various page replacement algorithms with example. (10 marks)

3 (b) Explain the working of EDF and RMA real time scheduling algorithms. (10 marks)

4 (a) Explain RAID with different levels. (10 marks)

4 (b) Consider a following a set of process, with length of CPU bursts given in milliseconds as follows:
i) Draw the Grant Charts for FCFS, SJF, Preemptive priority and RR (Quantum=2).
ii) What is the turnaround time of each process for adove algorithms?
iii) What is the time of each process for each of the above alorithms
iv) Which is algorithms results in minimum average waiting time.

5 (a) Explain the linked and indexed methods for allocating a disk space a file. (10 marks)

5 (b) How is a directory system useful in file organization? Explain Single level, Two level and Hierarchical directory system. (10 marks)

Write a notes on (any two):

6 (a) Cyclic Schedulers. (10 marks)

6 (b) Linux file system. (10 marks)

6 (c) Unix Security measures. (10 marks)