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

Memory pages, Applications allocate memory in terms of the number of bytes ...

Applications allocate memory in terms of the number of bytes that they need, but this level of granularity is too ?ne-grained for the operating system to manage the system memory i

Define an assembly language, Define an assembly language  Assembly lan...

Define an assembly language  Assembly language stands for a Low level programming language

What is a pure demand paging, What is a pure demand paging? When starti...

What is a pure demand paging? When starting implementation of a process with no pages in memory, the operating system sets the instruction pointer to the first instruction of t

Major advantages of microkernel approach to system design, Q. What are the ...

Q. What are the major advantages of the microkernel approach to system design? Answer: Benefits usually include the following (a) Adding a new service doesn't require modify

Explain signal handling, Signal handling A signal is used in UNIX syste...

Signal handling A signal is used in UNIX systems to inform a process that a particular event has occurred. 1. A signal is produced by the occurrence of a particular event.

What is time-stamping, time-stamping It is a method proposed by Lampor...

time-stamping It is a method proposed by Lamport, used to sequencing events in a distributed machine without the use of clocks. This process is intended to order events consis

What are the issues in designing a network-transparency, Transparency : ...

Transparency : Users must be able to access remote resources as though these resources were local. Transparency should as well promote user mobility. Users must be allowed to lo

Explain general graph directory, General graph directory The serious pr...

General graph directory The serious problem with using an acyclic-graph structure is ensuring that there are no cycles. When we insert links to an existing tree-structured dire

Medium term scheduler, Medium term scheduling is form of the swapping ope...

Medium term scheduling is form of the swapping operation. This attaches to processes that are in a suspended or blocked state. They are swapped out of real-memory storage until t

Assignment, You must use fork and pipe to complete this project. This proj...

You must use fork and pipe to complete this project. This project creates processes to add all numbers in a file. The user will enter a number (1, 2, or 4) of parallel processes

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