BITM Operating System

Define time sharing.

What might be the behavior of Round Robin algorithm, if its quantum is too large?

What are the two ways to terminate a process?

What is the problem of preemptive scheduling?

Draw a process state diagram. Describe how process state transition occurs.

What are the disadvantages of FCFS, Shortest Job Next and Priority scheduling algorithm?

Define critical section. How semaphore can be used to achieve mutual exclusion? Explain.

Define process.

What might be the contents of PCB?

Define the process scheduling mechanism of an OS.

What is a semaphore?

What are the advantages of IPC?

Define process. Explain how a process is created.

Which scheduling algorithm will be more appropriate between ‘shortest job first’ and ‘first come first serve’ for given set of processes in terms of average waiting time?

When a system is said to be deadlocked?

What is deadlock? Explain the banker’s algorithm.

Why do we need virtual memory?

Differentiate between page and frame.

Describe about fixed partition and variable partition memory strategies.

Why worst fit is better than best fit?

What is paging?

Explain paging scheme with supportive diagram.

Consider the following page reference string: 3, 3, 5, 4, 7, 1, 5, 5, 1, 4, 3, 7, 6, 3, 4, 1. How many page faults would occur for each of the following page replacement algorithms assuming 4 page frames?

i. LRU

ii. FIFO

List the different attributes of file protection.

What is bit vector?

How free space is managed in disk? Explain.

Define device driver.

Suppose a disk has 100 cylinders from 0 to 99 where the current head position is 46. If the disk access request is 75, 73, 2, 77, 37, 12, 11, 53 and 19 in order. Starting from the current head position calculate the total disk access time to serve all these request using:

a. FCFS algorithm

b. Shortest seek time first algorithm

The seek time from one cylinder to adjacent cylinder is 0.5 millisecond.

Which of the I/O strategy (polling, interrupt or DMA) is suitable for the following types of system? Give reason.

a. A system dedicated to controlling a single I/O devices.

b. A personal computer running a single-tasking OS.

c. A work station running as heavily used web server.

What do you mean by I/O optimization?

What do you mean by device management? Explain the polling process in I/O system.

Differentiate between security policy and mechanism.

Explain various authentication mechanism used in security system.

What is decryption?