R09 - December, 2011 - Regular Examinations - Set - 1.

B. Tech III Year I Semester Examinations, December-2011
OPERATING SYSTEMS
(COMMON TO CSE, IT)
Time: 3 hours Max. Marks: 75
Answer any five questions
All questions carry equal marks
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1.a) What are the various components of operating – system structure explain the simple and layered approach of operating system in details.
b) What is a system call? Explain how a user application invoking the open () system call is handled. [7 8]
2.a) Explain pre emptive and non preemptive scheduling.
b) Consider the following set of process that arrive at time o, with the length of the CPU burst given in milliseconds Process Burst time
P1 2 4
P2 3
P3 3
Calculate the average waiting time when the processes arrive in the following order:
a) P1,P2,P3 and b) P2,P3,P1
Provide the Gantt chart for the same. [7 8]
3.a) State and explain the critical section problem
b) By illustrating the structure of process P1, explain the Petersons solution to critical section problem. [7 8]
4.a) Write short notes on:
i) Fragmentation ii) Segmentation
b) Explain F1F0 page replacement algorithm necessary reference string and number of frames. [7 8]
5.a) Explain the resource - allocation graph algorithm for deadlock detection with relevant diagram
b) State and explain the steps involved in safety algorithm.
c) Illustrate Banker’s algorithm with proper example. [15]
6.a) Explain sequential and indexed file access methods.
b) Explain in detail the four approaches to free –space management. [7 8]
7.a) Explain the RAID level 1 through 6.
b) What are the various layers at which RAID can be implemented? [7 8]
c) Write short notes on interrupts.
8.a) Explain the three implementation of methods of access matrix
b) Give a detailed note on system and network threats. [7 8]
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