Operating System Interview Questions and Answers - Freshers & Experienced

What are the functions of operating system?

The operating system controls and coordinates the use of hardware among the different processes and applications. It provides the various functionalities to the users. The following are the main job of operating system.

- Resource utilization
- Resource allocation
- Process management
- Memory management
- File management
- I/O management
- Device management

Describe system calls and its type

System calls works as a mediator between user program and service provided by operating system. In actual situation, functions that make up an API (application program interface) typically invoke the actual system calls on behalf of the application programmer.

Types of System Call

System calls can be grouped roughly into five major categories:
Sr No.Example
1Process controlCreate process, terminate process,end,allocate and free memory etc
2File manipulationCreate file, delete file, open file, close file, read, write.
3Device manipulationrequest device, release device, read, write, reposition, get device attributes, set device attributes etc.
4Information maintenanceget or set process, file, or device attributes
5CommunicationsSend, receive messages, transfer status information

Explain Booting the system and Bootstrap program in operating system.

The procedure of starting a computer by loading the kernel is known as booting the system.

When a user first turn on or booted the computer, it needs some initial program to run. This initial program is known as Bootstrap Program. It is stored in read-only memory (ROM) or electrically erasable programmable read-only memory (EEPROM). Bootstrap program locates the kernel and loads it into main memory and starts its execution.

Describe Main memory and Secondary memory storage in brief.

Main memory is also called random access memory (RAM). CPU can access Main memory directly. Data access from main memory is much faster than Secondary memory. It is implemented in a semiconductor technology, called dynamic random-access memory (DRAM).

Main memory is usually too small to store all needed programs. It is a volatile storage device that loses its contents when power is turned off. Secondary memory can stores large amount of data and programs permanently. Magnetic disk is the most common secondary storage device. If a user wants to execute any program it should come from secondary memory to main memory because CPU can access main memory directly.

What are the advantages of multiprocessor system?

Systems which have more than one processor are called multiprocessor system. These systems are also known as parallel systems or tightly coupled systems.

Multiprocessor systems have the following advantages.

- Increased Throughput: Multiprocessor systems have better performance than single processor systems. It has shorter response time and higher throughput. User gets more work in less time.

- Reduced Cost: Multiprocessor systems can cost less than equivalent multiple single processor systems. They can share resources such as memory, peripherals etc.

- Increased reliability: Multiprocessor systems have more than one processor, so if one processor fails, complete system will not stop. In these systems, functions are divided among the different processors.

Is it possible to have a deadlock involving only one process? Explain your answer.

Deadlock with one process is not possible. Here is the explanation.

A deadlock situation can arise if the following four conditions hold simultaneously in a system.

- Mutual Exclusion.
- Hold and Wait.
- No Preemption.
- Circular-wait.

It is not possible to have circular wait with only one process, thus failing a necessary condition for Circular wait. There is no second process to form a circle with the first one. So it is not possible to have a deadlock involving only one process.

What is an operating system?

An operating system is a collection of software programs which control the allocation and usage of various hardware resources in the system. It is the first program to be loaded in the computer and it runs in the memory till the system is shut down.

Some of the popular Operating Systems are DOS, Windows, Ubuntu, Solaris etc.

What are its main functions?

The main functions of an OS are:

a. Process Management
b. Memory Management
c. Input/ Output Management
d. Storage/ File system management

What is a Kernel?

- Kernel is the part of OS which handles all details of sharing resources and device handling.
- It can be considered as the core of OS which manages the core features of an OS.
- Its purpose is to handle the communication between software and hardware
- Its services are used through system calls.
- A layer of software called shell wraps around the Kernel.

What are the main functions of a Kernel?

The main functions of a Kernel are:

- Process management
- Device management
- Memory management
- Interrupt handling
- I/O communication
- File system management
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Explain the meaning of Kernal.
Operating System Kernal - The kernel is the essential center of a computer operating system, the core that provides basic services for all other parts....
Operating System - What is a command interpreter?
Operating System - A command interpreter is the part of a computer operating system that understands and executes commands that are entered....
What is a daemon?
Operating System daemon - In Unix and some other operating systems, a daemon is a computer program that runs in the background, It is not under the direct control of a user.......
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mphee 04-15-2014
Good questions
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Neha 03-1-2014
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ashish 09-15-2013
difficult to copy and download
There is no question about your provided information really these are very useful for IT Exam preparation.

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vijay 02-12-2013
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archana 01-16-2013
operating system interview questions
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Anusha 12-22-2011
it's nice, but need much more...
sanga 11-6-2011