Operating Systems - May 2016
Computer Science Engg. (Semester 5)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1(a) List and explain the functions and services of an operating system and OS operations.(8 marks) 1(b) What are virtual machine? Explain VM-WARE architecture with a neat diagram.(8 marks) 1(c) Differentiate between multi-programming, multiprocessing and multitasking systems.(4 marks) 2(a) Explain process states with state transition diagram. Also explain PCB with a neat diagram.(8 marks) 2(b) What is IPC? Explain Direct and Indirect communication with respect to message pass systems.(5 marks) 2(c) Consider the following set of process arrival time and Burst time
A LARGER priority number has a higher priority
|Jobs||Arrival Time ms||Burst Time ms||Priority|
|A B C||A B C||A B C|
|P0||0 0 2||0 0 4||1 0 2|
|P1||1 0 0||2 0 1|
|P2||1 3 5||1 3 7|
|P3||6 3 2||8 4 2|
|P4||1 4 3||1 5 7|
ii) If a request from process P2 arrives for (002), can the request be granted immediately?(9 marks) 5(a) What are Translation load aside buffers (TLB)? Explain TLB in detail with a simple paging system with a neat diagram.(8 marks) 5(b) Given the memory partitions of 100K, 500K, 200K, 300K, and 600K apply First fir and last fit algorithm to place 212K, 417K, 112K, 426K.(6 marks) 5(c) Consider the following reference string 7012304230321201701 for a memory with three (03) frames. How many page Faults occur for LRU and FIFO page replacement algorithms? Which is efficient among both?(8 marks) 6(a) What is a file? Explain in detail different allocation methods.(8 marks) 6(b) What are directories? List different types of directory structures with examples. Mention their advantages and disadvantages.(8 marks) 6(c) Explain how free space is managed.(4 marks) 7(a) Let a disk drive has 5000 cylinders from 0 to 4999. Currently drive is at 143rd cylinder, and the previous request was at cylinder 125. Queue of pending request in FIFO order I 86, 1470, 913, 1774, 948, 1509, 1022, 130. What is the total distance the disk arm moves to satisfy all the pending requests for each of the following disk scheduling algorithms from current position i) FCFS ii) SCAN iii)LOOK.(12 marks) 7(b) What is protection? Distinguish between mechanism and policies. Explain briefly Acess matrix with domains as objects.(8 marks) 8(a) With a neat diagram explain in detail components of a Linux system.(7 marks) 8(b) Explain the different IPC mechanism available in Linux in detail.(8 marks) 8(c) Explain process scheduling kernel synchronization in detail.(5 marks)