Operating Systems For Computational Devices Semester 5 (May 2012)

Operating Systems For Computational Devices Semester 5 (Revised Course) (3 Hours) May 2012
GN-7049 [Total Marks : 100]
N.B:	(1)	Question No. 1 is compulsory.
	(2)	Attempt any four questions out of remaining six questions.
1.	(a)	What are the main advantages for an operating system designer of using virtual machine architecture? what is the main advantages for a user.	10
	(b)	Consider the following snapshot of the system.   Process Allocation Max Available   A  B  C  D A  B  C  D A  B  C  D P0 0  0  1  2 0  0  1  2 1  5  2  0 P1 1  0  0  0 1  7  5  0   P2 1  3  5  4 2  3  5  6   P3 0  6  3  2 0  6  5  2   P4 0  0  1  4 0  6  5  2           Answer the following questions using banker's algorithm.   (i)  Determine the total amount of resource of each type.   (ii) What is the content of need matrix?   (iii) Determine if the system is in safe state using safety algorithm.   (iv) If a request from process P1 arrives for (0, 4, 2, 0) can the request be granted immediately.	10
2.	(a)	On a disk with 1000 cylinders, numbers 0 to 999, compute the number of tracks the disk arm must move to satisfy all the requests in the disk queue. Assume that the last request serviced was at track 345 and head is moving towards track 0. Th queue in FIFO order contains requests for the following tracks : 123, 874, 692, 475, 105, 376. Perform the computation for the following disk scheduling algorithms. i)  FIFO  ii) SSTF  iii) SCAN	10
	(b)	What is RTOS? Give the classification of RTOS and comparison of any two RTOS.	10
3.	(a)	Consider the following snapshot of the process to be executed. Draw the Gantt chart and determine the average waiting time and averages turnaround time for FCFS, SJF (preemptive), SJF (nonpreemptive) and round robin (quantum=2) scheduling algorithm.   Process Arrival time Burst Time P1 0 4 P2 2 5 P3 4 6 P4 5 2 P5 6 1	10
	(b)	Describe Incode and FAT Structure.	10
4.	(a)	On a simple paging system with 224 bytes of physical memory 256 pages of logical address space and page size of 210 bytes. i)  Determine the no of bits in physical address. Specify the page frame? ii) How many entries are presenter in page-table? iii) How many bits are in logical address space?	10
	(b)	Suggest an implementation of binary semaphores that avoids busy waiting.	10
5.	(a)	What is kernel? Describe briefly the approaches of designing kernel.	10
	(b)	Consider the following page traces in a demand paging system with 3 page frames. 2,3,1,1,2,3,4,6,2,3,4,3,1,2,3. Determine the number of page faults and hit ratio using FIFO and LRU page replacement algorithm.	10
6.	(a)	Describe Programmed IO and DMA.	10
	(b)	Consider a disk having 8 surface. Each surfaces having an outer diameter of 16cm and inner of 6cm and inner track track space in 0.2mm. There are 32 sectors in each track. If disk address for reading a byte or sector on any surface track of disk is 27 bits. What is sector size in bytes if disk rotates at 3600rpm. What is effective data transfer rates in bytes/sec?	10
7.	Write short note on the following :-		20
	(a)	Monitor
	(b)	Distributor O.S
	(c)	Network O.S
	(d)	Symbian O.S

Also see Operating systems for computational devices question papers for December 2011