Common Operating System (OS) Interview Preparation Guide
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Operating System (OS) Interview Questions and Answers will guide every kind of job seeker because computer is the basic need for any organization so every one must have so of the basic idea of computer and the Operating System is the soul of computer. So this guide is for every one who want to know the basics of Operating System called as OS.

74 Operating System (OS) Questions and Answers:

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Common  Operating System (OS) Job Interview Questions and Answers
Common Operating System (OS) Job Interview Questions and Answers

1 :: What are the reasons for process termination?

☛ Normal completion
☛ Time limit exceeded
☛ Memory unavailable
☛ Bounds violation
☛ Protection error
☛ Arithmetic error
☛ Time overrun
☛ I/O failure
☛ Invalid instruction
☛ Privileged instruction
☛ Data misuse
☛ Operator or OS intervention
☛ Parent termination.

2 :: List the sub-components of I/O manager in Windows NT?

☛ Network re-director/ Server
☛ Cache manager.
☛ File systems
☛ Network driver
☛ Device driver

3 :: Tell me What is executive in Windows NT?

In Windows NT, executive refers to the operating system code that runs in kernel mode.

4 :: Explain DDks?

DDks are device driver kits, which are equivalent to SDKs for writing device drivers. Windows NT includes DDks.

6 :: Tell me What are the rings in Windows NT?

Windows NT uses protection mechanism called rings provides by the process to implement separation between the user mode and kernel mode.

7 :: What is drawback of MVT?

It does not have the features like:
☛ Ability to support multiple processors
☛ Virtual storage
☛ Source level debugging

8 :: List the possible threads a thread can have?

☛ Ready
☛ Standby
☛ Running
☛ Waiting
☛ Transition
☛ Terminated

9 :: Explain FtDisk in Operating System (OS)?

It is a fault tolerance disk driver for Windows NT.

10 :: Explain an idle thread?

The special thread a dispatcher will execute when no ready thread is found.

11 :: Explain mutant in Operating System (OS)?

In Windows NT a mutant provides kernel mode or user mode mutual exclusion with the notion of ownership.

12 :: Explain migration process?

It is the transfer of sufficient amount of the state of process from one machine to the target machine.

13 :: Explain the reasons for process suspension?

☛ Swapping
☛ Interactive user request
☛ Timing
☛ Parent process request

14 :: Explain process spawning?

When the OS at the explicit request of another process creates a process, this action is called process spawning.

15 :: Explain a drawback of MVT?

It does not have the features like:
☛ Ability to support multiple processors
☛ Virtual storage
☛ Source level debugging

16 :: Tell me is Windows NT a full blown object oriented operating system? Give reasons?

No Windows NT is not so, because its not implemented in object oriented language and the data structures reside within one executive component and are not represented as objects and it does not support object oriented capabilities.

18 :: Explain SMP?

To achieve maximum efficiency and reliability a mode of operation known as symmetric multiprocessing is used. In essence, with SMP any process or threads can be assigned to any processor.

19 :: What are the four layers that windows NT have in order to achieve independence?

☛ Hardware abstraction layer
☛ Kernel
☛ Subsystems
☛ System Services.

20 :: Tell me what has triggered the need for multitasking in PCs?

☛ Increased speed and memory capacity of microprocessors together with the support fir virtual memory
☛ Growth of client server computing

21 :: Explain page cannibalizing?

Page swapping or page replacements are called page cannibalizing.

22 :: Can you please explain the difference between demand-paging and pre-paging?

With demand paging, a page is brought into memory only when a location on that page is actually referenced during execution. With pre-paging, pages other than the one demanded by a page fault are brought in. The selection of such pages is done based on common access patterns, especially for secondary memory devices.

23 :: Can you please explain the difference between load-time dynamic linking and run-time dynamic linking?

For load-time dynamic linking: Load module to be loaded is read into memory. Any reference to a target external module causes that module to be loaded and the references are updated to a relative address from the start base address of the application module.
With run-time dynamic loading: Some of the linking is postponed until actual reference during execution. Then the correct module is loaded and linked.

24 :: What are placement and replacement algorithms In the context of memory management?

Placement algorithms determine where in available real-memory to load a program. Common methods are first-fit, next-fit, best-fit. Replacement algorithms are used when memory is full, and one process (or part of a process) needs to be swapped out to accommodate a new program. The replacement algorithm determines which are the partitions to be swapped out.

25 :: Tell me if you know how are the wait/signal operations for monitor different from those for semaphores?

If a process in a monitor signal and no task is waiting on the condition variable, the signal is lost. So this allows easier program design. Whereas in semaphores, every operation affects the value of the semaphore, so the wait and signal operations should be perfectly balanced in the program.
Operating System (OS) Interview Questions and Answers
74 Operating System (OS) Interview Questions and Answers