Tribhuvan University
Bachelor of Science in Computer Science and Information Technology
Semester 4 · TU Board 2080 (new course)
Course Title: Operating Systems (CSC264)
Full Marks: 60Pass Marks: 24Time: 3 hours
Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.
Group A
Attempt any TWO question.(2 × 10 = 20)
- 1.10
How DMA operation is performed? Consider a disk with 200 tracks and the queue has random requests from different processes in the order : 45, 48, 29, 17, 80, 150, 28 and 188. Find the seek time using FIFO, SSTF and SCAN. Assume the initial position of head as 100.
- 2.10
How do you distinguish between deadlock and starvation ? Describec. Explain working mechanism of TLB.
- 3.10
Why do we need to schedule process? Find the average waiting time and average turnaround time for the following set of processes using FCFS, SJF, RR (Quantum = 3) and shortest remaining time next.
Process
CPU brust time
Arrival time
P1
20
0
P2
25
15
P3
10
30
P4
15
45
Group B
Attempt any EIGHT question(8 × 5 = 40)
- 4.5
What is system call ? Describe the transition between different states of process.
Answer comingAlso asked in 2078
- 5.5
Discuss about contiguous and linked list file allocation technique.
Answer comingAlso asked in 2080
- 6.5
Why do we need virtual memory? Describe the sructure of a page table.
- 7.5
Illustrate the term safe and unsafe state in deadlock prevention with scenario.
- 8.5
How lock variable is used in achieving mutual exclusion? Describe.
- 9.5
Why do we need hierarchical directory system? Explain structure of disk.
- 10.5
Find the number of page fault using FIFO and LRU for the refrence string 4, 7, 6, 1, 7, 6, 1, 2, 7, 2 with frame size 3.
- 11.5
Define working set. How does clock replacement algorithm works?
- 12.5
Write short notes on :
- Inode
- RAID
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