Miyerkules, Pebrero 27, 2013

Research Topics

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

- 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.

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.

-File manager is allocates a file first through finding the secondary storage devices and after that , it loads the files to memory while they updates the records of the running file at the time. 

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

-Yes, because the property of a computer program whose successful execution (without recompilation) does not depend on the type of physical unit associated with a given logical unit employed by the program

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.

-The difference is in the interface which where they work together.

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.

-In real life the multi-file volume is just like our file that is only God can manage and knows our life will end.
As multi-volumes files is just like the Gods love which he share in his people and his people share their love back at him.

6.       As described in this chapter, which he share 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.

-No,its not feasible to combine both formats in a single disks because the two fields are in different areas.
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.

-It is difficult ti direct access because it is hard ti find the exact location of records , such as we suggest the variable-length record because it is easy to access file directly at the period of time.

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 file name and its complete file name.