CSCI 315 Final Exam Review

The questions for the final exam will be taken from/similar to/based on the following, in addition to the material on previous review sheets, the homework and lab exercises you've been assigned throughout the semester. While the material covered since the last exam has more weight, remember that the final is cumulative. Since last exam, we have covered the subjects in Chapter 13, Chapter 14.1-3, 14.7-9, and Most of the Chapter 15.

  1. Identify the following:

  2. What are the different ways of protecting a file (or a directory)?

  3. How is a file system organized?

  4. In the context of UNIX file systems, what does each of the following owner, group,others, mean? What does the protection read, write, execute mean?

  5. What are the different protection modes implemented in UNIX files?

  6. What problems can occur if links to directories are allowed in a directory structure?

  7. List three methods of allocating space for files, and explain for each how the operating system keeps track of the blocks in a file. What are the advantages and drawbacks of each method?

  8. How can free space for a file system be organized? Explain how the various methods work.

  9. Explain how the interrupt system works by giving an example of what happens when a device is ready to transmit data to the CPU. Be specific and explain the steps involved.

  10. Explain how a DMA data transfer occurs.

  11. True or False: caching and buffering are two different words for the same thing. Explain your answer.

  12. Explain how abstraction and encapsulation are involved in the design of the Application-I/O interface. What is the mechanism by which an application initiates I/O operations?

  13. Explain what happens when an application program issues an I/O request, e.g. cout in C++, all the way from the application program to the input or output devices.

  14. What is the key criterion used to measure different disk scheduling algorithm?

  15. For a given sequence of disk requests, compute the number of tracks (cylinders) that the disk head has to travel through.

  16. Explain the three components of time delay in a disk access: seek time, rotational time, transfer time.

  17. Explain storage hierarchy, how each level contributes to computing in general.

  18. Explain how a piece of data is sent from one computer and received by another computer.

  19. Explain the three approaches for authentication covered in class.

  20. Explain the benefits and drawbacks of password authentication systems.

  21. How is password information stored in a Unix system? What can be done to help thwart a dictionary attack on this information?

  22. What is a one-way function?

  23. True or false: the only obstacle to better computer security is the need to develop more advanced techniques.