2006 Visvesvaraya Technological University Fifth Semester B.E. Degree Examination , Dec.06 / Jan. 07 Operating Systems Question paper

2006 Visvesvaraya Technological University Fifth Semester B.E. Degree Examination , Dec.06 / Jan. 07 Operating Systems Question paper

Fifth Semester B.E. Degree Examination, January/February 2006
Computer Science/Information Science and Engineering
Operating Systems
Time:3hrs.) (Max.Marks:100
Note: 1. Answer any FIVE questions.
1. Write relevant figures/diagrams wherever necessary.
1. (a) What is an operating system (OS)? Differentiate between the two views of OS. (5marks)
(b) List the essential properties of the following types of operating systems:
i) Batch
ii) Time sharing
iii) Distributed.
(9marks)
(c) Mention the activities connected with process management, memory management of and file management, (6marks)
2. (a) Compare virtual machine and no virtual machine. (3marks)
(b) Write the structure of PCB and the state transition diagram. Mention the function of each state. (6marks)
(c) Describe the function of long term, medium term and short term schedulers with a block diagram. (6marks)
(d) Write a program in C language to create a child process and synchronize with the main program. (5marks)
3. (a) Differentiate between onetoone and manytomany model used formultithreading implementation. (4marks)
(b) Define throughput and response time in a multiprogramming system. (2marks)
(c) Explain round robin scheduling policy. (6marks)
(d) Consider the following set of processes. The processes have arrived in the order P1,P2, P3, P4, P5 all at time Q.
i) Draw four Ganttt charts illustrating ;the execution of these processes using FCFS,SJF, a no preemptive priority ( a smaller priority number implies a higherpriority ), and RR (quantum=1) scheduling
ii) What is the turnaround time of each process for each process for each of thescheduling algorithms in part (I)? (8marks)

2. (a ) Explain critical section problem. Discuss on efficient algorithm which canmeet all the requirements to solve this problem. (7marks)
(b) Write a monitor solution to the dining philosopher’s problem. (5marks)
(c) What a is deadlock? What are the necessary conditions for a deadlocksituation? (3marks)
(d) Describe banker’s algorithm for deadlock avoidance.

5. (a) Determine the total swap time for a user process o0f size 4 MB with a disktransfer rate of 10 MB per second and latency time is 12 msec. (3marks)
(b) Describe both internal and external fragmentation problems encountered in acontiguous memory allocation scheme. (6marks)
(c) Explain paged memory allocation scheme. (8marks)
(d) What is virtual memory concept? Explain the address translation mechanism.
(3marks)

6. (a) Define:
i) Thrashing
ii) Belady’s anomaly and
iii) Effective access time in demand paging. (3marks)
(b) consider the following page reference
1,2,3,4,2,1,5,6,2,1,2,2,3,7,6
How many page fauits would occur for the following replacement algorithmsAssuming three page frames in the main memory? All page frames are initially empty so that first unique pages will all cost one fault each
1)FIFO
2)LRU
3)Optimal. (9marks)
(d)Differentiate between two level directory structured and tree structured directory.(4marks)
(d)Explain the structure of disk. (4marks)

7. (a)Explain the structure of disk. (6marks)
(b)Explain the 6 file operations. (6marks)
(c)Discuss on SCAN disk scheduling method. Also compare with CSCAN scheduling. (8marks)

8. (a) Describe areas matrix model of protection. (7marks)
(b)Explain the different program threats. (6marks)
(c)Discuss on the process management function in Unux OS.