If you are looking for a job in operating systems, then you definitely have a good prospect in this field. The job market for operating system professionals is growing with speedy technological advancement according to the US Department of Labor Statistics. If you have applied for this job and your resume has been shortlisted by a potential employer, they will call you for an interview. The operating system interview questions are easy to answer if you have a clear concept on the subject matter coupled with professional experience.
Operating system is the most important component that runs on a computer system. It is a program that manages both software and hardware resources of a computer device. It is used to extract information or input from the keyboard, send the output to the computer display (screen), manage and control files on disk and peripherals like printer, scanner, etc. Some of the recognized operating systems are Windows, Ubuntu Linux, Mac OS, etc., to name a few.
We have presented some sample interview questions to give you an idea on the type of questions that may come across your way.
Q: What is an operating system?
A: “Operating system is the software which forms the link between the hardware of the computer and the user interface. It is the bridge between the kernel of the machine and the user interface programs.”
Q: What is the difference between multitasking system and timesharing system?
A: “Timesharing system is the process by which all running programs are allocated a set amount of time to use the system resources. Once the time is up, the resources are allocated to the next program in queue.
Multi-tasking system is the process by which programs are allocated resources as and when they are executed. This helps in multiple programs being executed simultaneously. This is much faster than time sharing, as more than one program can be executed at the same time.”
Q: Is there any difference between the virtual and physical memory?
A: Physical memory is the RAM in the computer, whereas virtual memory is the page memory used by the operating system when the physical memory available is not enough to execute the program.
Q: What is a page fault?
A: “A page fault is an interrupt to a program when it tries to access a page that has a map in the address space, but is actually not loaded in physical memory. This results due to incorrect coding of programs or incorrect memory addresses or faulty RAM.”
Q: How many strategies are there to deal with deadlocks? Can you list all of them?
A: “There are 4 strategies to deal with deadlocks. They are:
Q: What are the deadlock operating conditions that can be used to prevent further deadlocks?
A: “These are the conditions that can be used for preventing deadlocks:
Q: What is the function of resource allocator in an operating system?
A: “Resource allocator is a program of the operating system that is used to assign the requested resources to the processes. This is done in an economical way so that the utilization of resources is optimally allocated.”
Q: What are kernel threads? Please explain in detail.
A: “Kernel threads are responsible for the creation of threads in the operating system. They are also responsible for the scheduling of the kernel space and are used to manage the space in the kernel.”
Q: What is a program?
A: “A program is a set of code or lines of code, which in effect, contain a list of instructions to be executed by the operating system. These lists of instructions should be accepted by the operating system. Programs are passive as they themselves are not performing any activity or using any resource to execute.”
Q: What is a process? Is it active or passive?
A: “When the instructions listed in a program are executed, it’s called process. A process is active as it uses the resources of the computer to perform certain tasks.”
Q: What does the operating system do when a sub program is called?
A: “When a sub program is called, the operating system stores all the temporary results in process status word, also called PSW, and the return address is stored in the stack.”
Q: What is a socket? How does it differ from a pipe?
A: “A socket is a transient object that is used for inter process communication, whereas a pipe is a linear array of bytes that is used solely as an I/O stream.”
Q: Can we call the operating system a process?
A: “An operating system is indeed a process. It’s controlled by its kernel.
Q: What does DHCP stand for?
A: “Dynamic Host Configuration Protocol is DHCP. It assigns network settings dynamically from a server.”
Q: What is fault tolerance?
A: “Fault tolerance is a feature of the kernel. It is a mechanism of ensuring that the hardware is not spoilt due to a program error.”
Q: What are virtual machines?
A: “A virtual machine (VM) is an emulation of a machine that behaves like a physical machine. Virtual machines fall into two categories - system virtual machine and process virtual machine.”
Read and understand the above operating system interview questions and answers thoroughly. Detailed preparation and practice are extremely essential before you face the real interview.