A bit of assistance with questions 8 and 9 please? . The prk non-networked syste
ID: 3738280 • Letter: A
Question
A bit of assistance with questions 8 and 9 please?
. The prk non-networked systems. In a distriBuled Op information needs to be noted in the PCB in order for the Processor to successfully manage processes correctly? .If your NOS had four nodes, how many operating systems would it have? Explain your reasons for your answer. 7. If your DO/S had four nodes, how many operating systems would it have? Explain your answer. Explain, in your own words, the steps a DOS File Manager uses to open a read data from it, update that data, and close the file. Do these steps change if file, the data is not changed? Describe the reasons for your answer. 94 Several levels of file access were discussed in this chapter, including read/write, read-only, execute-only, and no access. If you are maintaining a database con- taining confidential patient information and need to restrict UPDATE to only 5 individuals, allow only 15 others to view the database, and disallow all data- base access to any other users, which access level would you assign to the three groups of people? For each of the three groups describe every type of access granted to each one. 10. Describe in detail how a DO/S protects a file from access or modification by an unuthorized user Compare it to NOS file protection.Explanation / Answer
8)
Open a file:
Almost all the file systems has hierarchical structure in which there is a root directory called master directory which will have info of all the files on the system. To open a file, locate master directory and navigate through the hierarchy to find the file location.
Read a File:
To read a file setup a channel to file and read it using normal file access processes. If file does not have read permission then this will no be allowed.
Also if it's currently being modified then it might not allow reading.
Write a File:
Again setup a channel to file and try to write it. Read can also be done parallely but write should not be shareable, it's always exclusive. So first a lock has to be acquired on the file and other processes will wait for the lock being released. When writing is done, unlock the file.
Close the file:
Closing a file means releasing the handle of file.
These steps might change depending on the type of file or the permissions of that file as some different level of file access permissions require different level of processing.
9)
For 5 individuals to have update permission: READ/WRITE/EXECUTE
For 15 to view database: READ-only
Others: No Access