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

Compute the effective instruction time on the system, Q. An operating syst...

Q. An operating system sustains a paged virtual memory using a central processor with a cycle time of 1 microsecond. It costs an additional one microsecond to access a page other

What is file allocation?, What is File Allocation? The structure that ...

What is File Allocation? The structure that offers the FAT file system its name is the file allocation table . In order to know what this important table does, you should fir

Determine the requiring variables on the scope of a thread, Determine the R...

Determine the Requiring Variables on the Scope of a Thread It is very common in server application programs to require variables on the scope of a thread. To provide such a sco

Operating system.., What is the use of FIFOs in client-server applications

What is the use of FIFOs in client-server applications

Explain doscreatethread functions used in the os/2, Explain DosCreateThread...

Explain DosCreateThread Functions Used in the OS/2  DosCreateThread(&threadID,MyThreadFunction,arg,flags,stackSize) DosCreateThread creates a thread within the context of th

#title.paging, explain hierarchical,hashed and inverted paging

explain hierarchical,hashed and inverted paging

Unix, difference between soft link and hard links

difference between soft link and hard links

Write xeyes on command line, Ask question #Minimum 100 words accepteWrite a...

Ask question #Minimum 100 words accepteWrite an xeyes command to display a window that is: ? SIZE: ¦ 400 pixels wide ¦ 300 pixels tall ? LOCATION: ¦ 100 pixels from the right edge

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