Cochin University Exam Papers BE CS 6th Semester Operating Systems September 2010

Cochin University Exam Papers BE CS 6th Semester

Operating Systems September 2010


CS/IT 603 Operating Systems

(2006 Scheme)


(Answer ALL questions)

I. (a) Write a note on: (i) Pipe (ii) Shell.

(b) Write the usage of process table.

(c) What is meant by Fifty Percent Rule?

(d) Explain the memory management using Linked Lists.

(e) What is meant by Trojan Horse Attack?

(f) Explain the features of RAID.

(g) Write the conditions for Deadlock.

(h) Write a note on Deadlock Modelling . 


II. (a) Write a note on : (i) Semaphores (ii) Monitors.

(b) Describe the concept of Producer-Consumer problem with message passing.


III. Five Batch jobs A through E, arrive at a computer centre at almost the same time.

They have estimated running times of 10,6, 2,4 and 8 minutes. Their priorities are 3,5,2, 1 and 4 respectively, with 5 being the highest priority. For each of the following scheduling algorithms, determine the mean process turnaround time.

(i)  Round robin

(ii) Priority scheduling

(iii) First in First Served (Run in order 10,6, 2,4, 8)

(i) Shortest Job First


IV. (a) What is meant by fragmentation? What are the various mechanisms for avoiding the fragmentation?

(b) Write short notes on: (i) Swapping  (ii) Virtual Memory.


V. (a) If FIFO page replacement is used with four page frames and eight pages, how many page faults will occur with the reference string 7103017232, if the four frames are initially empty? Repeat the same reference string for LRU also and find no. of page faults?

(b) Describe the design issues for Paging Systems.


VI. (a) Explain various design principles for Security.

(b) Compare the SCAN and C-SCAN algorithms for Disk Arm Scheduling.



VII. (a) Describe various protection mechanisms.

(b) Write a note on Interrupts.


VIII. (a) Explain the deadlock detection algorithm for one resource of each type.

(b) Write a note on Resource Trajectories.


IX. (a) Describe various layers in a UNIX system.

(b) Write a short note on UNIX file system.

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