in English Suomeksi toisella puolella

Operating Systems II                                 
Course examination 2.5.2006

Write in each answer sheet your name, signature, id-number, course name, and page nr/total nr of pages.

NOTE: Answer only to four (4) questions out of five (5). If you answer to all questions, then the best answer is left out.
The recommended maximum length for each answer is 2 pages.
The exam is worth 60 exam points and they will be scaled down to 50 points towards your grade.

  1. [15 p] Scheduling
    1. SMP
    2. Real time systems

  2. [15 p] Consider virtual memory Clock page replacement algorithm, when each page has both R-bit (viitattu, referenced or accessed recently) and M-bit (modified).
    1. What is the original problem that this algorithm solves? How does this Clock page replacement algorithm work?
    2. When is this Clock algoritmi activated? Who activates it? Does it always terminate?
    3. Who sets new values for R- and M-bits and when?

  3. [15 p] Linux ext2fs file system
    1. What is an inode and what information does it have?
    2. What is a hard link and how is it implemented in this system?
    3. What is a soft link and how is it implemented in this system?
    4. What advantages/disadvantages do hard links have when compared to soft links?
    5. Compare ext3fs to this system? Advantages? Disadvantages?

  4. [15 p] Windows 2000 (W2K) File System (NTFS)
    1. NTFS Master File Table (MFT): basic idea and use, location on disk
    2. MFT implementation of very small, normal size and very large files
    3. How is NTFS error recoverability implemented? What types of errors can be recovered from?

  5. [15 p] Operating system data and utility program protection in Linux and in Windows 2000.
    1. How is operating system data and utility program protection implemented in these systems?
    2. How can a user level program access these services?
    3. For example, a user wants to change his/her password. How is this type of access to protected data (e.g., password) implemented in these systems?