Interviewing

How to Answer Operating System Interview Questions

If you’re in a technology field, you are likely familiar with using an operating system (OS). Operating systems are the engines that power computing resources for all employers in the digital age. Many roles in IT may need to answer operating system interview questions. In this article, you’ll learn about operating system interview questions with example answers.

Why do employers ask operating system interview questions?

If you are applying for a job in technology, you may be asked to answer operating system interview questions. Operating systems provide the functionality to computers and computing technology, like smartphones, tablets and other devices. Without an operating system, even a very basic one, a computer would be practically useless. A computer requires a computing system to tell it what to do, and that’s where the OS comes in. 

Businesses of all types and sizes require operating systems to be effective. For this reason, you may be tasked with answering important questions about the operating systems of business-critical technology.

Operating system questions with sample answers

Here are a few operating system questions with sample answers to help you prepare for an upcoming interview:

What is a kernel?

This is an introductory type question that offers very basic knowledge of operating systems. To answer this question, briefly define what a kernel is in reference to an operating system.

Example: ‘An OS kernel, or known simply as a kernel, is a piece of the operating system that launches applications connecting them to data processing computing channels. It facilitates the exchange of call and response and information throughout a computing device.’

What classifications exist for server systems?

There are two important classifications of server systems when operating systems are involved. List the two and briefly describe their differences to answer this question fully.

Example: ‘Server systems classifications can be as follows: file server or computer server systems. Computer server systems represent a model where a user-interface allows clients (users, browsers or other clients) to send commands through the computing system to get a response. In file server systems, provisions offer the functionality to do things like create and update records and data.’

What is the goal of multiprogramming?

Multiprogramming is an important processing capacity for CPU utilization. To answer this question, you should describe the goal of multiprocessing in terms your audience will understand.

Example: ‘Multiprogramming is a processing capability where a process is always running to optimize CPU resources.’

Explain FCFS

FCFS is a technical term that stands for first come, first serve. To answer this question, you should explain the important details of first come, first serve.

Example: ‘FCFS is a type of scheduling algorithm that processes requests in sequential order of how they are allocated.’

What is the difference between a thread and a process?

Threads and processes represent terms that are inherent to operating systems. To best show your understanding of how threads and processes function in an OS, describe each one in terms of their differences.

Example: ‘A thread is a component of a process. They share some of the structural properties of a process and, for that reason, are sometimes considered lightweight versions of processes, in and of themselves. However, threads cannot run independently from each other, which is why processes are also important.’

Why would you use multithreaded programming?

There are a few key benefits of multithreaded programming. To correctly answer this question, list them.

Example: ‘Benefits of using multithreaded programming include enabling greater resource sharing and responsiveness as well as being a precursor to computing in a multiprogramming environment. Any company that strives for a multiprogramming approach might implement multithreaded programming.’

What is deadlock?

When processes are deadlocked it can slow down business operations. Show an understanding of deadlock by describing it. 

Example: ‘When multiple processes are running, they may become deadlocked when each process waits for the other to finish before it starts.’

What conditions are required for deadlock?

There are four conditions required for a deadlock to occur. Avoiding all four conditions simultaneously helps system admins avoid deadlock. Explain what each condition is to answer this question.

Example: ‘The four conditions required for deadlock are mutual exclusion, no preemption, circular wait, and hold and wait. Each is defined as:

  • Mutual exclusion. Represents a resource unable to be shared across the computing environment.
  • No preemption. Without preemption, the operating system can’t take a waiting resource back until a process has completed.
  • Circular wait. Processes are waiting for one another to finish.
  • Hold and wait. Resources are being held in a hold-and-wait pattern where they aren’t released until another resource is being held.’

Explain thrashing

Thrashing is a problem that can occur to the OS, and it’s something that a system admin might have to solve. To display an understanding of thrashing, describe it in plain terms.

Example: ‘Thrashing is an issue that occurs when the operating system begins to breakdown after spending too long processing page faults. If page faults are slow and execution doesn’t occur, this can lead to a collapse of a computing device.’

Define virtual memory

Virtual memory is a process that could be used for processes to be executed outside of a software’s physical memory units. It can help execute programs when there isn’t enough memory to do so. For this reason, an applicant may be asked to answer questions about virtual memory. To answer this question, define it clearly.

Example: ‘Virtual memory is used in memory management. It allows administrators to run processes when there isn’t enough memory to run those processes natively. Virtual memory creates the illusion of a large amount of memory for each user, however, it is really powered by the hard disk not the RAM, like traditional memory.’