Explain two level directory, Operating System

Assignment Help:

Two Level Directory

This kind of structure overcomes the problems of assigning unique names to the files. Thus there need not be any confusion among users.

In this kind of structure each user has a user file directory (UFD). The UFDs have an alike structure except each lists the files of a single user. As soon as a user starts or logs in the system's master file directory (MFD) is searched. The MFD is indexed by the account number or the user name and each entry points to the UFD for that user. Once a user searches for a particular file only his own UFD is searched and so different users may have the same names as long as all the file names within each UFD are unique.

A two level directory is able to be thought of as an inverted tree of height 2. The root of the tree is the MFD in addition to its descendents are the UFDs whose descendents are the files. 

Disadvantages:

            This structure detaches one user from the other. This is an benefit when the users are completely independent of each other but is a drawback when the users want to cooperate on some task and to access one another's files.

 

2000_Two Level Directory.png


Related Discussions:- Explain two level directory

How does user specify block to be fetched in direct access, How does user s...

How does user specify block to be fetched in direct access? By specifying the relative block number, relative to first block in file, which is block 0.

Deadlock prevention, While it is hard to resolve a deadlock which has been ...

While it is hard to resolve a deadlock which has been detected, fortunately it is fairly easy to prevent deadlocks from ever happening. The key is that the conditions above for dea

Process destruction, Most process abstractions support processes being dest...

Most process abstractions support processes being destroyed when the program terminates, or in response to a specific kill directive. There are two common implementations, one a "p

Unsafe state in a deadlock-avoidance system, Question: A set of process...

Question: A set of processes are in a deadlock state when every process in the set is waiting for an event that can be caused by only another process in the set. (a) There

Hardware and software requirements for virtual memory?, What are the hardwa...

What are the hardware and software requirements for virtual memory? The hardware required for virtual memory is a secondary memory and page table. The page table should have th

Explain a working of file control block, Explain a working of file control ...

Explain a working of file control block A file control block (FCB) has information about the file, containing ownership, permission, and location of the file contents. The log

What do you understand by active directory domain, Question: a) What ...

Question: a) What do you understand by Active directory domain in Windows Server 2008? Support your answer with a diagram. b) Distinguish between active directory trees

Describe virtual memory, What is virtual memory? Virtual memory is a me...

What is virtual memory? Virtual memory is a method that allows the execution of processes that might not be completely in memory. It is the separation of user logical memory fr

Bounded and unbounded buffer, Ask question #Minimum 100 difference between ...

Ask question #Minimum 100 difference between bounded and unbounded buffer words accepted#

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd