Operating Systems - April / May 2010 Question Paper


Anna university
B.E./B.Tech. DEGREE EXAMINATION, APRIL/MAY 2010
Fourth Semester
Computer Science and Engineering
CS2254 — OPERATING SYSTEMS
(Common to Information Technology)
(Regulation 2008)

Time : Three hours Maximum : 100 Marks
Answer ALL Questions

PART A — (10 × 2 = 20 Marks)

1. Mention the objectives and functions of an operating system.
2. Define thread. Differentiate user threads from kernel threads.
3. What is a semaphore? State the two parameters.
4. What is deadlock? What are the schemes used in operating system to handle
deadlocks?
5. Differentiate a page from a segment.
6. What is meant by thrashing? Give an example.
7. Mention the objectives of file management system.
8. Differentiate the various file access methods.
9. What is the need for disk scheduling?
10. What does swap-space management mean?

PART B — (5 × 16 = 80 Marks)

11. (a) (i) Explain the operating system structure and its components. (Marks 8)
(ii) Explain briefly IPC in Linux. (Marks 8)

Or

(b) (i) Explain Process Control Block. (Marks 4)

(ii) Describe the differences among short-term, medium-term, and long-term scheduling. (Marks 4)

(iii) Describe the Inter Process communication in client-server systems. (8)

12. (a) (i) Distinguish between preemptive and non-preemptive scheduling. Explain each type with an example. (Marks 8)
(ii) What is synchronization? Explain how semaphores can be used to deal with n-process critical section problem. (Marks 8)

Or

(b) (i) Discuss the issues in multiprocessor and real-time scheduling. (Marks 8)

(ii) Explain Banker's deadlock-avoidance algorithm with an illustration. (Marks 8)

13. (a) (i) Discuss how memory is allocated in variable partition multiprogramming. (Marks 6)
(ii) Explain memory management in Linux. (Marks 10)

Or

(b) (i) Discuss segmentation in detail. Compare it with paging. (Marks 8)
(ii) Explain FIFO, LRU and Second-chance page replacement algorithms with an example reference string. (Marks 8)

14. (a) (i) Explain linked file allocation method. (Marks 6)
(ii) Describe Windows XP file system in detail. (Marks 10)

Or

(b) (i) What is the role of Access matrix for protection? Explain. (Marks 5)
(ii) What is meant by free space management? Explain. (Marks 5)
(iii) Explain the directory structure of Linux operating system. (Marks 6)

15. (a) (i) Explain the services provided by a kernel I/O subsystem. (Marks 8)
(ii) Explain and compare the C-LOOK and C-SCAN disk scheduling
algorithms. (Marks 8)

Or

(b) (i) Write an elaborate note on RAID. (Marks 6)
(ii) Explain in detail the salient features of Linux I/O. (10)