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 different types of systems calls with suitable example.

Explain the structure of an operating system and discuss system calls and their importance.

Explain OS design and implementation issues. What is spooling and buffering?

Write the difference between batch and multiprogramming operating systems.

Explain how protection is provided for the hardware resources by the operating system?

Explain CPU scheduling criteria and describe different / preemptive scheduling algorithms.

What is indefinite blocking/starvation and why must wait() and signal() semaphore operations be atomic, showing that non-atomic execution can violate mutual exclusion?

Define process synchronization and explain Peterson's solution for mutual exclusion.

Draw Gantt chart and find completion sequence and average waiting time for Round Robin with quantum 2 and FCFS.

Calculate average waiting time using FCFS scheduling for given burst times with arrival time 0.

Explain the process concept and operations on processes.

Explain the critical section problem and semaphores.

Explain the process state transition diagram in a multiprogramming environment and describe the fields of a Process Control Block (PCB).

Draw Gantt charts for FCFS and pre-emptive priority scheduling and calculate average waiting time and average turnaround time.

Explain how the four necessary conditions for deadlock hold in the dining-philosophers problem and how deadlock can be avoided by eliminating any one condition.

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

Draw Gantt chart and find normalized turnaround time and average waiting time for preemptive priority and Round-Robin with quantum 4.

Given memory partitions 100 KB, 500 KB, 200 KB, 300 KB and 600 KB in order, place processes 212 KB, 417 KB, 112 KB and 426 KB in order using first-fit, best-fit and worst-fit and determine which is most efficient.

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.

What are the differences between internal and external memory fragmentation?

Calculate the number of bits in a logical address for a paging system with given physical memory, logical pages, and page size.

Explain deadlock and its necessary conditions.

Describe deadlock prevention, avoidance, and detection techniques.

Explain memory management techniques including fixed and dynamic partitioning.

Given memory blocks 100 KB, 500 KB, 200 KB and 300 KB, allocate a 212 KB process using First-Fit and Best-Fit.

What are the conditions for deadlock? Explain deadlock detection and recovery.

Explain the difference between logical and physical addresses.

Consider the following segment table: What are the physical addresses for the following logical addresses?

Draw the resource allocation graph for given processes, resources and edges and determine if there is a cycle/deadlock, including after adding a new request edge.

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

Explain demand paging, including address translation mechanism, page table implementation, advantages, and effective access time with page-fault probability.

Explain virtual memory and demand paging.

Explain page replacement algorithms and the concept of thrashing.

Define optimal page replacement algorithm and explain why it is considered the best.

What is the difference between local and global page allocation? What are their respective advantages and disadvantages?

For disk with 5000 cylinders, head at 143 (prev 125) and queue 86, 1470, 913, 1774, 948, 1509, 1022, 1750, 130, compute total head movement for FCFS, SSTF, SCAN/LOOK.

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

Write short notes on distributed system, thrashing, inter-process communication, and system calls.

What are the typical access rights that may be granted or denied to a particular user for a particular file?

Explain disk scheduling and the different disk scheduling algorithms.

Describe various directory structures.

Discuss Remote Procedure Call (RPC) in detail.

For disk head initially at 53 with queue 98, 183, 37, 122, 14, 124, 65, 67, compute total head movement using FCFS, SSTF, SCAN and C-SCAN.

What do mean by file attributes and operations? Briefly explain file access methods.

Which file-allocation method is suitable for a system whose main task is database management and why?

Explain the problems with simply returning a deleted file's blocks to the free list, how to overcome them, and any resulting trade-offs and resolutions.

Explain how allocating disk storage at different granularity levels can improve performance and what modifications to free-space management are needed to support it.

When multiple interrupts from different devices appear at about the same time, a priority scheme could be used to determine the order in which the interrupts would be serviced. Discuss what issues need to be considered in assigning priorities to different interrupts.

Write a short notes on: (Any three)