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

Tlb replacement algorithm, Suppose a logical address space is 1KB, and the ...

Suppose a logical address space is 1KB, and the page-size is 16 bytes. Assume no page is in the main memory for this process initially and the pure demand paging is used. Current f

Explain the facilities of a debug monitor, Facilities of a Debug Monitor ...

Facilities of a Debug Monitor Facilities of a debug monitor are like this: Setting breakpoints in the program Initiating a debug conversation while control reaches

How can a user program disturb the normal operation, How can a user program...

How can a user program disturb the normal operation of the system? a) Issuing illegal I/O operation. b) By accessing memory locations within the OS itself. c) Refusing to

Algorithm for reconstructing a logical ring, Q. Present an algorithm for re...

Q. Present an algorithm for reconstructing a logical ring after a process in the ring fails? Answer: Typically distributed systems utilize a coordinator process that performs

Windows admin need it, Windows admin need it Project Description: We ...

Windows admin need it Project Description: We want to protect an executable on operating system level , so the process could be visible among all users while the executable r

Is disk scheduling useful in a single-user environment, Is disk scheduling,...

Is disk scheduling, other than FCFS scheduling, useful in a single-user environment? Explain your answer. In a single-user environment, the I/O queue usually is blank. Requests

Vehicle tasks using semaphores, Gopher Gallery consists of a shopping mall ...

Gopher Gallery consists of a shopping mall and a cart ride that covers  the 150 acre habitat. There are m visitors and n single-person vehicles. Visitors  stroll around the mall at

Explain deadlock avoidance, Deadlock Avoidance It's a method to evade ...

Deadlock Avoidance It's a method to evade deadlock by careful resource scheduling. This approach to the deadlock problem foresees deadlock before it actually occurs. This a

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

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