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

Explain the purpose of command-line application, Question: a) The follo...

Question: a) The following questions refers to Windows XP networking: i) Briefly, explain how a host joins a network using DHCP? ii) Which IP address could be assigned to a

What inference does recovery in distributed systems, Q. Consider a distrib...

Q. Consider a distributed system with two sites A and B. Consider whether site A can distinguish among the following: a. B goes down. b. The link between A and B goes down.

Synchronization, As we already know, threadsmust ensure consistency; otherw...

As we already know, threadsmust ensure consistency; otherwise, race conditions (non-deterministic results) might happen. Now consider the "too much milk problem": two people share

Define a linker program, Define a linker program  A linker program lin...

Define a linker program  A linker program links the program along with other programs required for its execution.

What is a two state process model?, What is a two state process model? ...

What is a two state process model?   At any time a process is being implementing by a processor or not. Therefore a process may be in Running or not running state. When an Ope

What do you meant by the term ergonomics, Question 1: "Three entities m...

Question 1: "Three entities must be accountable and responsible for accident prevention." (a) List and explain these three entities. (b) Discuss the role of workers in ma

Typical virtual memory layout, Using pages makes it easier to manage the wh...

Using pages makes it easier to manage the whole memory, avoiding excessive fragmentation and waste. As an analogy, think of Tetris, but with only square blocks: it is relatively ea

Explain linked allocation, Linked allocation With linked allocation, ev...

Linked allocation With linked allocation, every file is a linked list of disk blocks; the disk blocks might be scattered anywhere on the disk. The directory has a pointer to 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