Published by: Dikshya
Published date: 24 Mar 2023
POKHARA UNIVERSITY
Level: Bachelor Semester: Fall Year: 2022
Programme: BCIS Full marks: 100
Course: Operating System Pass Marks: 45
Time: 3 hrs.
Candidates are required to answer in their own words as far as practicable. The figures in the margin indicate full marks.
Section ” A”
Very Short Answer Questions
Attempt all the questions. [10*2]
Section “B”
Descriptive Answer Questions
Attempt any six questions. [6*10]
11. a) What are system calls and Shell commands? Explain Batch and Embedded Operating System with examples.
b) What do you mean by Operating System structures? Differentiate between monolithic and microkernel structure highlighting their advantages and disadvantages.
12. Define short term and long term scheduler. Calculate average waiting time and average turnover time for given set of processes using First come first serve preemptive shortest job first and round robin scheduling algorithm with quantum size 3.
|
Processes |
Arrival time |
Burst time |
|
A |
0 |
4 |
|
B |
1 |
3 |
|
C |
3 |
4 |
|
D |
5 |
6 |
a. FCFS
b. SJF
c. Preemptive SJF
d. RR (Q=3)
13. What do you mean by race condition? List out the rules to deal with race conditions. Explain Peterson’s solution for mutual exclusion.
14.a) What do you mean by memory management? Explain contiguous and non-contiguous memory allocation in brief.
b) Explain about the coalescing compaction process with a diagram.
15. Differentiate between pooling and interrupt. Suppose a disk has 200 cylinders from 0 to 199 where the current head position is 50. If the disk access request is 82, 170,43, 140, 24, 16, 190. Starting from the current head position, calculate the total disk access time to serve these requests using:FCFS,SSTF,SCAN and LOOK (assume head moving towards higher value in case of SCAN and LOOK).
16. Differentiate between files and directories. Explain in brief about different file implementation techniques.
17. Express your view on "DOS as middleware". Explain RPC mechanism as a communication method in distributed systems in detail.
Section "C"
Case Analysis
18. Read the case situation given below and answer the questions that follow: [20]
Suppose you are a system administrator for a large enterprise that uses a computer system with multiple processes competing for shared resources. One of the issues you must consider is the potential for deadlocks, which can occur when two or more processes are blocked, waiting for resources held by each other.
Consider a system with three processes, P1, P2, and P3, and three resources, A, B, and C. Process Pl requires resources A and B to complete its execution, process P2 requires resources B and C, and process P3 requires resources C and A..
a) Analyse the scenario to determine if a deadlock has occurred. If so, identify the processes involved and the resources they are holding
b) Suggest two methods for detecting deadlocks in this system and describe how each method works.
c) Discuss two strategies for resolving deadlocks in this system, including the benefits and limitations of each approach.
d) Evaluate the above scenario and suggest how the deadlock can be resolved using one of the methods or strategies you discussed.
POKHARA UNIVERSITY
Level: Bachelor Semester: Fall Year: 2022
Programme: BCIS Full marks: 100
Course: Operating System Pass Marks: 45
Time: 3 hrs.
Candidates are required to answer in their own words as far as practicable. The figures in the margin indicate full marks.
Section ” A”
Very Short Answer Questions
Attempt all the questions. [10*2]
Section “B”
Descriptive Answer Questions
Attempt any six questions. [6*10]
11. a) What are system calls and Shell commands? Explain Batch and Embedded Operating System with examples.
b) What do you mean by Operating System structures? Differentiate between monolithic and microkernel structure highlighting their advantages and disadvantages.
12. Define short term and long term scheduler. Calculate average waiting time and average turnover time for given set of processes using First come first serve preemptive shortest job first and round robin scheduling algorithm with quantum size 3.
|
Processes |
Arrival time |
Burst time |
|
A |
0 |
4 |
|
B |
1 |
3 |
|
C |
3 |
4 |
|
D |
5 |
6 |
a) FCFS
b) SJF
c) Preemptive SJF
d) RR (Q=3)
13. What do you mean by race condition? List out the rules to deal with race conditions. Explain Peterson’s solution for mutual exclusion.
14. a) What do you mean by memory management? Explain contiguous and non-contiguous memory allocation in brief.
b) Explain about the coalescing compaction process with a diagram.
15. Differentiate between pooling and interrupt. Suppose a disk has 200 cylinders from 0 to 199 where the current head position is 50. If the disk access request is 82, 170,43, 140, 24, 16, 190. Starting from the current head position, calculate the total disk access time to serve these requests using:FCFS,SSTF,SCAN and LOOK (assume head moving towards higher value in case of SCAN and LOOK).
16. Differentiate between files and directories. Explain in brief about different file implementation techniques.
17. Express your view on "DOS as middleware". Explain RPC mechanism as a communication method in distributed systems in detail.
Section "C"
Case Analysis
18. Read the case situation given below and answer the questions that follow: [20]
Suppose you are a system administrator for a large enterprise that uses a computer system with multiple processes competing for shared resources. One of the issues you must consider is the potential for deadlocks, which can occur when two or more processes are blocked, waiting for resources held by each other.
Consider a system with three processes, P1, P2, and P3, and three resources, A, B, and C. Process Pl requires resources A and B to complete its execution, process P2 requires resources B and C, and process P3 requires resources C and A..
a) Analyse the scenario to determine if a deadlock has occurred. If so, identify the processes involved and the resources they are holding
b) Suggest two methods for detecting deadlocks in this system and describe how each method works.
c) Discuss two strategies for resolving deadlocks in this system, including the benefits and limitations of each approach.
d) Evaluate the above scenario and suggest how the deadlock can be resolved using one of the methods or strategies you discussed.