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

Differences among user-level threads and kernel-level thread, Q. What are t...

Q. What are two differences among user-level threads and kernel-level threads? Under what situations is one type better than the other? Answer: (1) User-level threads are un

Minor page fault , Minor page fault :I f the page is loaded in memory at t...

Minor page fault :I f the page is loaded in memory at the time the fault is started, but is not checked in the memory management unit as being loaded in memory, then it is named a

Peripharal device, 50 peripharal device name ,diagram and uses

50 peripharal device name ,diagram and uses

Define ageing, Define Ageing Ageing is a method of enhancing the priori...

Define Ageing Ageing is a method of enhancing the priority of process waiting in Queue for CPU allocation

Command line interface, College life is tough.  Eating pizza for every meal...

College life is tough.  Eating pizza for every meal is hitting you hard.  You are looking at working out to stay healthy.  You found a web site that tells you how many calories eac

Name two differences between logical and physical addresses, Q. Name two di...

Q. Name two differences between logical and physical addresses? Answer: A logical address doesn't refer to an actual existing address rather it refers to an abstract address in

Explain short term scheduling, Short term scheduling The short term sch...

Short term scheduling The short term scheduler as well known as the dispatcher executes most frequently and makes the fine grained decision of which process to execute next. Th

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