NALANDA OPEN UNIVERSITY QUESTION, 2017, MCA, Part-III,Paper-XXI (Operating System)

NALANDA OPEN UNIVERSITY QUESTION, 2017, MCA, Part-III,Paper-XXI (Operating System) 

                                                                              2017
                                                                       Time: 3 hours
                                                                      Full Marks: 80
                                       Answer any five questions. All questions carry equal marks.

1. What is a Semaphore? Give solution to sleeping barber problem with the help of semaphore.

2. Draw the Gantt chart for the FCFS and SJF policy, considering any four set of process that arrive at time 0, with the length of CPU time given in milliseconds. Also calculate the average waiting and average turnaround time. (Assume four process with variable time period in milliseconds).

3. What is segmentation? Explain with an example. How segmentation different from paging.

4. Explain algorithm for deadlock prevention. give a suitable example to explain the algorithm.

5. Give a short note on mutual exclusion in a distributed system. Explain token based mutual exclusion in the context of it.

6. Implementation FCFS,SCAN , LOOK and 8C - LOOK scheduling for the following disk queues:-
    50,91,150,42,130,98,18,138,140.
    Assume that the disk head is initially at cylinder 50. Cylinder the total head count.

7. Discuss hardware support in paging. How is overlay different from swapping? explain.

8. Explain pipes and filters in UNIX (with examples). Give a diagram to explain various states of a process. Explain the PCB or TCB also.

9. Explain paging address translation by and give suitable diagrams and examples also:-
    (i) Direct Mapping.
    (ii) Associative Mapping

10. Give short notes on the following:-
      (i) Disk organization in UNIX.
      (ii) DOS and NOS.
      (iii) Multiprocessor Interconnection.
      (iv) Macintosh OS.