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

Write a note on the usage of semaphores, Write a note on the usage of semap...

Write a note on the usage of semaphores. Semaphore is a synchronization tool and it is a variable having integer values. It is accessed only by two standard atomic operations w

Task decomposition and data decomposition, Discuss the concepts of  task de...

Discuss the concepts of  task decomposition  and  data decomposition  within the context of parallel programming. Parallel programming or parrelel computing is the simultaneo

Advantages and disadvantages of multiprogramming, Q. Advantages and disadva...

Q. Advantages and disadvantages of multiprogramming? Advantages 1.    High CPU utilization. 2. It appears that many programs are allotted CPU almost concurrently. D

Determine a policy that is not valid page replacement policy, Determine a p...

Determine a policy that is not a valid page replacement policy?  RU policy (Recurrently used) is not a valid page replacement policy.

What is a message passing system, Question 1 What is a message passing sys...

Question 1 What is a message passing system? Discuss the desirable features of a message passing system Question 2 Discuss the implementation of RPC Mechanism in detail Q

Explain benefits of time-sharing system, Under what circumstances would a ...

Under what circumstances would a user be better off using a time-sharing system, rather than a personal computer or single-user workstation? When there are some other users, th

Deadlock detection, Deadlocks can be detected while the program is running,...

Deadlocks can be detected while the program is running, by running cycle detection algorithms on the graph that de?nes the current use of resources. De?ne this graph as follows:

Virtualization, What factors are involved in choosing the host operating sy...

What factors are involved in choosing the host operating system?

Explain multiprocessing operating system, Multiprocessing - An Operating S...

Multiprocessing - An Operating System proficient of utilizing and supporting more than one computer processor. Below are some instances of multiprocessing Operating Systems. Li

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