CS3451 Introduction to Operating Systems Important Questions

CS3451 Introduction to Operating Systems Important Questions

Unit 1

1. What is the main difficulty that a programmer must overcome in writing an operating system for a real-time Environment?
2. Describe three general methods for passing parameters to the operating system.
3. Consider a computing cluster consisting of two nodes running a database. Describe two ways in which the cluster software can manage access to the data on the disk. Discuss the benefits and disadvantages of each.
4. List five services provided by an operating system, and explain how each creates convenience for users. In which cases would it be impossible for user-level programs to provide these services? Explain your answer.
5. List down the objectives and functions of Operating Systems.
6. Detail the various types of user interfaces supported by Operating Systems.
7. Explain various structures of Operating System.
8. Explain the purpose and importance of system calls in detail with examples.

Unit 2

1. Describe how processes are created and terminated in an operating system.
2. Give an example of a situation in which ordinary pipes are more suitable than named pipes and an example of a situation in which named pipes are more suitable than ordinary pipes.
3. Consider the following set of processes, with the length of the CPU burst time given in milliseconds. 
   

    i) Draw Gantt’s Chart illustrating the execution of these processes using FCFS, SJF and Round Robin (with quantum = 1) scheduling techniques.
   (ii) Find the Turnaround time and waiting time of each process using the above technique.

4. Describe how deadlock is possible with the dining-philosopher’s problem.
5. What are semaphores? How do they implement mutual exclusion?
6.  Explain the techniques used to prevent deadlocks.

Unit 3 

1. Explain the difference between internal and external fragmentation.
2. On a system with paging, a process cannot access memory that it does not own. Why? How could the operating system allow access to additional memory? Why should it or should it not?
3. Illustrate how pages are loaded into memory using demand paging.
4. Under what circumstances do page faults occur? Describe the actions taken by the operating system when a page fault occurs.
5. Explain the need and concept of paging technique in memory management.
6.  Consider the page reference string: 1 2 3 4 1 3 0 124 1 and 3 page frames. Find the page faults, hit ratio and miss ratio using FIFO, optimal page replacement and LRU schemes.

Unit 4

1. Write detailed notes on file system interface and file system structure.
2. 
   

   

3. Is disk scheduling, other than FCFS scheduling, useful in a single-user environment? Explain your answer.
4. Describe three circumstances under which blocking I/O should be used. Describe three circumstances under which nonblocking I/O should be used.
5. Consider a file system in which a file can be deleted and its disk space reclaimed while links to that file still exist. What problems may occur if a new file is created in the same storage area or with the same absolute path name? How can these problems be avoided?
6. Contrast the performance of the three techniques for allocating disk blocks (contiguous, linked, and indexed) for both sequential and random file access.

Unit 5

1. Describe four virtualization-like execution environments, and explain how they differ from “true” virtualization.
2. Why are VMMs unable to implement trap-and-emulate-based virtualization on some CPUs? Lacking the ability to trap and emulate, what method can a VMM use to implement virtualization?
3. Describe the three types of traditional hypervisors.
4.  Discuss about the mobile operating system with suitable example.
5. Explain various types of virtual nachines and their implementations in detail.
6. Explain the architecture of Android OS.
7. Compare iOS with Android OS.