• Attempt any five questions.
• All questions carry equal marks.
Describe the evolution of the operating system in detail.
What are the major services of an operating system with regard to process management? Explain.
Explain different disk allocation methods in detail.
Following is the snapshot of a CPU:
| Process | CPU Burst | Arrival Time |
|---|---|---|
| P1 | 10 | 0 |
| P2 | 29 | 1 |
| P3 | 03 | 2 |
| P4 | 07 | 3 |
| Draw the Gantt chart and calculate the turnaround time and waiting time of the jobs for |
i) FCFS (First Come First Served)
ii) SJF (Shortest Job First)
iii) SRTF (Shortest Remaining Time First)
iv) RR (Round Robin with time quantum 10) scheduling algorithms
Consider the following snapshot of a system:
| Processes | Allocation | Max | Available |
|---|---|---|---|
| A B C D | A B C D | A B C D | |
| P0 | 0 0 1 2 | 0 0 1 2 | 1 5 2 0 |
| P1 | 1 0 0 0 | 1 7 5 0 | |
| P2 | 1 3 5 4 | 2 3 5 6 | |
| P3 | 0 6 3 2 | 0 6 5 2 | |
| P4 | 0 0 1 4 | 0 6 5 6 |
i) What is the content of the matrix Need?
ii) Is the system in a safe state?
iii) If a request from process P1 arrives for (0, 4, 2, 0) can the request be granted immediately?
What is Demand paging? Explain.
Discuss about segmentation with an example.
Differentiate Synchronous and Asynchronous I/O operations
How I/O request are transferred to hardware devices?
Consider the page reference string 1, 0, 2, 5, 3, 0, 1, 0, 2, 4, 0, 3, 0, 4, 2, 4, 3, 4, 1, 4, 0. How many page faults occur for the Optimal and LRU Page replacement algorithms with 4 frames each?
Describe the actions taken by a thread library to context-switch between user level threads.
Mutual Exclusion
Disk Mounting
Virtual File Systems
User level and Kernel level threads
