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

Blocking locks, We have talked about blocking locks, which voluntarily yiel...

We have talked about blocking locks, which voluntarily yield, and spinlocks, which just spin until they acquire the lock. At ?rst, it seems like spinlocks are verywasteful, and tha

What is virtual file system?, What is virtual file system? A Virtual f...

What is virtual file system? A Virtual file system switch (VFS) or Virtual file system is an abstraction layer   on top of a more concrete file system. The purpose of a VFS

Explain single-user systems, We have stressed the need for an operating sys...

We have stressed the need for an operating system to make efficient use of the computing hardware. When is it appropriate for the operating system to forsake this principle and to

Solve a generalized dining philosopher problem, In this project, you will i...

In this project, you will implement the Chandy and Misra's (CM) algorithm using POSIX Threads (Pthreads).   The algorithm  is a distributed algorithm to solve a generalized dining

Default domain controllers policy gpo, Question: (a) Distinguish betwee...

Question: (a) Distinguish between local and active directory Group Policy in Windows Server 2008? (b) Describe the three areas of account Policies that can be managed thro

List sample file types, List sample file types, based on use, on the VAX un...

List sample file types, based on use, on the VAX under VMS.  source programs (.BAS, .FOR, .COB, .PLI, .PAS, .MAR)  data files (.DAT)  text files (.TXT)  command proced

Advantage of minimizing the file space, Q. a number of systems automaticall...

Q. a number of systems automatically delete all user files when a user logs off or a job terminates unless the user explicitly requests that they be kept other systems keep all fil

Explain the real time operating system, Explain the Real Time Operating Sys...

Explain the Real Time Operating System A real-time operating system comprises definite, fixed time constraints. Processing should be done in the defined constraints, or the sys

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