Operating Systems (AL-501) - Important Questions

What is an operating system? Explain its different types/classification.

Explain the services and functions provided by an operating system, including how they are provided through system calls and commands with examples.

Explain the main functions and functionalities of an operating system in managing hardware and software resources.

What is kernel? Describe various operations performed by kernel?

Define System calls. Discuss the challenges associated with low-level implementation and portability issues of system calls.

Answer the following:

What is meant by a System call? How it can be used? How does an application program use these calls during execution?

Describe the evolution of the operating system in detail.

Explain the major services of an operating system with regard to process management.

Define a file and explain the file concept in operating systems. Discuss the user's view and system programmer's view of a file system with suitable examples.

Discuss disk space allocation methods: contiguous, linked and indexed allocation with diagrams, advantages and disadvantages.

Explain directory structures in file systems and discuss file protection mechanisms and access control methods.

Discuss free space management on disk: bit vector, linked list, grouping and counting.

Explain different disk space allocation methods in detail.

Explain the organization of hard disk and the steps involved in disk formatting and file system creation.

Explain challenges of contiguous allocation and calculate ending block for contiguous allocation.

Describe the concept of file protection and access control in operating systems.

Explain the producer-consumer problem and its solution using semaphores, showing how synchronization and mutual exclusion are achieved.

Define deadlock and explain the four necessary conditions / characterization for deadlock to occur.

Explain the Banker's algorithm for deadlock avoidance, including deadlock conditions.

Using Banker's algorithm on a given snapshot, compute the Need matrix, determine if the system is in a safe state with safe sequence, and check if a request can be granted.

What do you understand by system call? List and explain four system calls used for process management.

Define semaphore? Give a scheme for implementation of semaphore primitives?

Define message passing and shared memory interprocess communication?

What are threads and multithreading? Compare user-level threads and kernel-level threads in terms of creation, scheduling, performance and overhead.

Explain difference between preemptive and non-preemptive scheduling, why strict non-preemptive scheduling is unlikely in a computer centre, and operation of multilevel scheduling.

What do you understand by context switching and various processes involved in it?

Describe Dekker's solution?

Draw Gantt chart and calculate average waiting time and average turnaround time using FCFS and SRTF scheduling algorithms.

Given memory partitions 100K, 500K, 200K, 300K, 600K in order, show how First-fit, Best-fit and Worst-fit place processes 212K, 417K, 112K and 426K in order and determine which algorithm makes the most efficient use of memory.

Explain the concept of paging and how it helps in memory management

Define virtual memory and discuss its importance and benefits in modern operating systems.

Explain non-contiguous memory allocation techniques. Describe paging, segmentation and paged segmentation with neat diagrams.

Discuss paging hardware with TLB

Explain demand paging and determine the number of page faults for a given reference string using FIFO, LRU and Optimal page replacement algorithms.

Given a page reference string, calculate the number of page faults using LRU and Optimal page replacement algorithms.

Explain how memory management is implemented in Unix/Linux operating systems.

Define dynamic linking and loading. Why is it useful in virtual memory systems?

What is demand paging? Explain the concept.

Discuss about segmentation with an example.

Differentiate between synchronous and asynchronous I/O operations.

What is real time operating system? What is difference between hard real time and soft real time operating system?

What is spooling and what are its advantages over buffering?

Discuss protection and security issues in operating systems and explain mechanisms such as authentication, access control, encryption and auditing.

Explain I/O buffering and discuss its importance in improving I/O performance. Describe single buffering, double buffering and circular buffering.

Discuss Disk scheduling algorithms?

Explain the role of the Kernel I/O Subsystem and how I/O requests are transformed into hardware operations.

Define Virtualization and its applications in operating systems.

Explain principles of protection and protection mechanisms using access matrix, protection domains and access control lists.

How I/O request are transferred to hardware devices?

Write a short note on any two: