IT221- quiz # 1 -chapter 8

Research Topics

A. Research the size of operting system software by finding the amount of secondary storage (disk) space required by different versions of the same operating system of different operating systems. If their sizes are substantially different, explain why that may be the case, such asplatform issues, features, etc. Cite your sources.

Answer:

Win 3.1 ~15MB, although it requires at least MS-DOS 6.22 to boot, so tack on another few megs.
Win 95 b ~80MB
Win 98 SE ~300MB
Win 2000 Pro ~720MB with no service packs. After SP4, it's around 1GB.
Win XP Pro, ~1.2GB with SP2.
Suse 9.2
Slackware 10.1
Ubuntu
Linspire 4.5
Mandriva 10.1

http://www.overclockers.com/forums/showthread.php?t=397609

their sizes are substantially different because an operating system tells a computer where to find data, and where to find various services, such as drivers for your screen. It points to them.
The Internet acts very much like an operating system, everything on the Internet points to something: pages, data, images, services such as search, maps, etc.

B. Consult current literature to research file-naming conventions for four different operating systems (not including UNIX, MS-DOS, Windows, or Linux). Note the acceptable range of characters, maximum length, case sensitivity, etc. Give Examples of both acceptable and unacceptable filenames. For extra credit, explain how the File Managers for those operating systems shorten long filenames (if they do so) in their internal lists to make them easier to manipulate. Cite your sources.

Exercises

1. Explain in your own words why the file deallocation is important and what would happen if it did not occur on a regular basis.

Answer:

File deallocation is important because It really depends on the operating system. Most modern operating systems will deallocate all files assigned to a process when the process terminates, and will flush all internal I/O buffers prior to that, so closing files is mainly a question of neatness, not necessity. Because deallocation means to release a computer resource that is currently assigned to a program or user, such as memory or a peripheral device. It would only happen on an irregular basis and people would come in and have nothing to do.

2. Describe how the File Manager allocates a file to a single user. List the steps that you think would be followed and explain your reasoning.

Answer:
The file manager handles all files on secondary storage media. To perform these tasks, file management must:

• be able to identify the numerous files by giving unique names to them
• maintain a list telling where exactly each file is stored, how many sectors on the medium it occupies, and in which order those sectors make up the file
• provide simple and fast algorithms to read and write files in cooperation with the device manager
• give and deny access rights on files to users and programs
• allocate and deallocate files to processes in cooperation with the process manager
• provide users and programs with simple commands for file handling

3. Is device independence important to the File Manager? Why or why not? Describe the consequences if that were not the case.

Answer:
Device independence is important to the file manager because device independence is the process of making a software application be able to function on a wide variety of devices regardless of the local hardware on which the software is used.

4. Do you think that file retrieval is different on a menu-driven system and command driven-system? Explain your answer and describe any differences between the two. Give an example of when each would be preferred over the other.

Answer:
  •All these processes were the same such that they do not automatically eradicate a file but prompt for the user's confirmation.

5. Imagine one real-life example of each: a multi-file volume and multi-volume file. Include a description of the media used for storage and a general description of the data in the file.

Answer:

6. As described in this chapter, files can be formatted with fixed-length fields or variable field lengths. In your opinion, would be feasible to combine both formats in a single disk? Explain the reasons for your answer.

Answer:
            •Yes, that can be done.You would just create your partitions and format them with your file system of choice.

7. Explain why it's difficult to support direct access to files with variable-length records. Suggest a method for handling this type of file direct access is required.

Answer:
 •It is difficult because you have to use a different structure for each variable record 
               type.

8. Give an example of the names of three files from your own computer that do not reside at the root or master directory. For each file, list both the relative filename and its complete filename.

Answer:
•exe - 1701_Gold_Trn_P.exe
              •ttf - Dovah.ttf