Explain two level directory, Operating System

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. 


            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

Posted Date: 6/19/2013 3:10:13 AM | Location : United States

Related Discussions:- Explain two level directory, Assignment Help, Ask Question on Explain two level directory, Get Answer, Expert's Help, Explain two level directory Discussions

Write discussion on Explain two level directory
Your posts are moderated
Related Questions
What is meant by file management systems? File Management systems are as well referred to as simply a file system .File system is the system that an OS operating system or prog

The term thread-safe in computer programming describes that routine or portion of the program that may be called from multiple programming threads without uncalled for interactions

Define the Scheduling in Multitasking Earlier we learned the concepts and advantages of multitasking. In a system in which one or more tasks( threads or processes) attempt to s

What is graceful degradation? In multiprocessor systems, failure of single processor will not halt the system, but only slow it down by sharing the work of failure system by ot

File structure Certain files must conform to a needed structure that is understood by the operating system. The operating system may consist that an executable file has a parti

protection in operating system

Q. Consider the subsequent page reference string: 1, 2, 3, 4, 2, 1, 5, 6, 2, 1, 2, 3, 7, 6, 3, 2, 1, 2, 3, 6. How many page faults would take place for the following replace

Determine what the expansion of nested macro calls follows  The expansion of nested macro calls follows the Last in First out (LIFO) rule.

What do you mean by semaphore?  Semaphore : A synchronization variable that acquires on positive integer values. Invented by the Dijkstra P (semaphore): an atomic proce