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

What are the advantages of indexed allocation, What are the advantages of I...

What are the advantages of Indexed allocation? The benefits are a. No external-fragmentation problem b. Solves the size-declaration problems. c. Supports direct access

What are the use of job queue, What are the use of job queues, ready queues...

What are the use of job queues, ready queues and device queues? As a process enters a system they are put in to a job queue. These queues having of all jobs in the system. The

How is the NTFS namespace planned, Q. How is the NTFS namespace planned? Ex...

Q. How is the NTFS namespace planned? Explain. Answer: The NTFS namespace is prearranged as a hierarchy of directories where every directory uses a B+ tree data structure to

Basic server model, Suppose we want to program a Web server; we could easil...

Suppose we want to program a Web server; we could easily do so without using concurrency, as follows: while(true) wait connection read from socket and parse url look up url cont

#title:cs604, Consider a scenario of post mailbox, there are two processes ...

Consider a scenario of post mailbox, there are two processes named sender S and receiver R. Both processes can communicate with each other by name along with message. You need to I

Explain the tlsgetvalue (tlsindex) function, Explain the TlsGetValue (TLSin...

Explain the TlsGetValue (TLSindex) Function Executing this function will return the thread local storage data associated with this thread. The pointer returned will be the one

Explain internal fragmentation, Explain internal fragmentation The Inter...

Explain internal fragmentation The Internal fragmentation signifies to the result of reserving a piece of space without ever intending to use it. This space is wasted that this

Explain worst fit algorithm, Worst Fit Algorithm Here we obtain the la...

Worst Fit Algorithm Here we obtain the largest space available for the smallest. Therefore after that process entered there will be much more space remaining. In this space we

How can an index file be used to speed up, How can an index file be used to...

How can an index file be used to speed up the access in direct-access files? Have an index in memory; the index gives the key and the disk location of its corresponding record.

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