Research Topic:
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 system. If their sizes are substantially different ,explain why that may be the case, such as such platform issues ,features,etc.
= Win 2000 Pro ~720MB with no service packs. After SP4, with a size of 1GB.
Win XP Pro, ~1.2GB with SP2
Win 98 SE ~300MB
Win 95 b ~80MB
Win 3.1 ~15MB, although it requires at least MS-DOS 6.22 to boot
OpenSuse 9.2
Slackware 10.1
Ubuntu
Linspire 4.5
Mandriva 10.1
B.) Consult current literature to research file-naming conversations 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 For extra credit,explain how the File Managers for those operating systems shorthen long filenames in their internal list to make them easier to manipulate.Cite your sources.
= insensitiveReserved Characters – noneAcceptable – kL209_pp.doxUnacceptable – fill\this.t!LMAC OS HFSAcceptable range of characters – 8-bit setMaximum length – 255 file name Case sensitivity – insensitive & perservationReserved Characters – :Acceptable – kL209_pp.doxUnacceptable – fill:this.t!L
DEC VAX VMSAcceptable range of characters – A-Z 0-9 $ - _Maximum length – 255 file name & 32
extensionsCase sensitivity – insensitiveReserved Characters – noneAcceptable – kL209_pp.doxUnacceptable –
fill\this.t!LISO 9660Acceptable range of characters – A-Z 0-9 _ .Maximum length – 255 file name Case sensitivity –
Exercises
1.Explain in your own words why file deal location is important and what would happen if it did not occur on a regular basis.
= In my own words is depends on the Operating System used.other modern operating system will deallocate all the files assigned to a process when the process terminates and it will flush all internal I/O buffers prior to that,the closing files is mainly a question of neatness, but not necessity. Some of the other bound I/O management libraries may also retain an internal application-side buffers that aren't flushed off unless the file is explicity closed.In this case of problem,I might close a file before terminating in order to avoid file corruption or lost of some documents, in some other cases i might lose updates.
2. Describe how the File manager allocates a file to a single user. List the steps that you think would be followed and explain you reason.
= 1. Keep track of where each file is stored.\
2. Use a policy that will determine where and how the files will be stored, making use to efficiency use the available storage apace and provide efficient access to the files.
3. allocate each file when a user has been cleared for access to it, then record its use.
4. deallocate the file when the file is to be returned to storage, and communicate its availability to others who may be waiting for it.
* in this steps you can avoid file errors and some conflicts.if there is another way to avoid a file error..you must first test it.
3.Is device independence important To the File Manager? Why or Why not? Describe the consequences if that were not the case.
4.Do you think file retrieval is different on a menu-driven system and a command-driven system?
=
5.Image one real-life example of each: a multi-file volume and a multi-volume file. Include a description of the media used for storage sand a general description of the data on the file.
= In real life the multi-file volume is just like tree that bears a fruit while multi-volume file is also like a fruit that came from a tree and it is shared to the people for them to eat.
6.As described in the chapter, files can be formatted with fixed-length fields or variable-length. In your own opinion, would it be feasible to combine both formats in a single disk? Explain the reasons for your answer.
= No, it is not feasible to combine both formats in a single disk because the two fields are in both different areas to format.
7.Explain why it’s difficult to support direct access to file with variables-length records. Suggest a method for handling this type of file is direct access is required.
= they are difficult to support or access because it is hard to calculate exactly where the record is located.
8.Give an example of the names of three files from your own PC that do not reside at the root or master directory. For each file, list both the relative filename and it's complete filename.
=
