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

Process, what common event leads to the creation of a process?

what common event leads to the creation of a process?

Mutual exclusion variable, Since each thread has its own processing space t...

Since each thread has its own processing space therefore communication between threads will need to be done through a common global variable. Since multiple threads can access the

Bag of tasks, The producer-consumermodel above has a standard human analogy...

The producer-consumermodel above has a standard human analogy of an assembly line. Humans have specialized skills, however, whereas threads running the same program do not need to

What are the various file operations, What are the various file operations?...

What are the various file operations? The six basic file operations are Creating a file Reading a file Writing a file Repositioning within a file Tr

Os installation, Question: OS Installation / File system a) Why is NTFS...

Question: OS Installation / File system a) Why is NTFS portioning preferred over FAT16 or FAT32 when security is of primary concern? b) State a situation or an application w

What is multiprogramming, Q. What is Multiprogramming? Multiprogrammin...

Q. What is Multiprogramming? Multiprogramming When two or more programs are in memory at the same instance, sharing the processor is referred to multiprogramming opera

Explain swapping, Explain Swapping Swapping is a method of temporarily ...

Explain Swapping Swapping is a method of temporarily removing inactive programs from the memory of computer system.

Assignment, Ask question #Minimum 100 words accDefine Hashing System. Descr...

Ask question #Minimum 100 words accDefine Hashing System. Describe the Hashed page table with example and mapping figure.

Describes responsibilities of the I/O manager, Q. Describes responsibilitie...

Q. Describes responsibilities of the I/O manager? Answer: The I/O manager is responsible for file systems and device drivers and network drivers. The I/O manager keeps follow

Memory organization and decoding, In a  p system each part (RAM, ROM, I/O) ...

In a  p system each part (RAM, ROM, I/O) has a unique set of numbers. The allocation of these numbers is usually stated in the form of a memory map. This is a plot of data bus agai

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