Operating System (IT-501) - Important Questions

Define an operating system and explain its objectives, functions and major services, including user-oriented and system-oriented services.

Define what an operating system is and explain the different types of operating systems with examples.

Explain CPU scheduling criteria and describe different preemptive and non-preemptive scheduling algorithms.

Explain the process concept and operations on processes.

Consider 3 processes P1, P2 and P3 which require 5, 7 and 6 time units and arrive at time 0, 1 and 4. Draw Gantt chart and find completion sequence and average waiting time for Round Robin with quantum 2 and FCFS.

What is meant by indefinite blocking or starvation? Show that if the wait() and signal() semaphore operations are not executed atomically, then mutual exclusion may be violated.

Explain the critical section problem, its requirements/conditions and illustrate with an example.

Consider the page reference string 1,2,3,4,2,1,5,6,2,1,2,3,7,6,3,2,1,2,3,6. Calculate number of page faults using LRU, FIFO and Optimal replacement algorithms.

Explain deadlock and its necessary conditions.

Using Banker's algorithm, compute the Need matrix, check if the system is in a safe state and give the safe sequence, and decide if a resource request can be granted.

Explain memory management techniques including fixed and dynamic partitioning.

Given five memory partitions of 100 KB, 500 KB, 200 KB, 300 KB and 600 KB in order, how would each of the first-fit, best-fit and worst-fit algorithms place processes of 212 KB, 417 KB, 112 KB and 426 KB in order? Which algorithm is most efficient?

Suppose a disk drive has 5000 cylinders numbered 0 to 4999. The drive is currently serving a request at cylinder 143 and the previous request was at cylinder 125. The queue of pending requests in FIFO order is 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130. Compute total head movement for FCFS, SSTF, SCAN and LOOK.

Explain file management in an operating system, including file organization and access methods.

Describe various directory structures.

Explain introduction to distributed systems, its types, advantages and design issues with suitable examples.