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

Define swapping, Define swapping. A process requires being in memory to...

Define swapping. A process requires being in memory to be executed. Though a process can be swapped temporarily out of memory to a backing store and then brought back into memo

In which page replacement policy balady’s anomaly occurs, In which page rep...

In which page replacement policy Balady’s anomaly occurs? FIFO (First in First Out)

Explain additional-reference-bits algorithm, Additional-reference-bits algo...

Additional-reference-bits algorithm We can keep an 8-bit byte for every page in a table in memory. The operating system shifts the reference bits right 1 bit, discarding the lo

Implementing group policies in a windows environment, Question: (a) As...

Question: (a) As a System administrator, elaborate on how you can manage computer accounts in Active Directory of Windows Server 2008? (b) Explain the following user p

For what reason would such a scheme be useful, Q. A Burroughs B7000/B6000 ...

Q. A Burroughs B7000/B6000 MCP file is able to be tagged as sensitive data. When such a file is removed its storage area is overwritten by some random bits. For what reason would

Explain the resource ownership by platform, Explain the Resource Ownership ...

Explain the Resource Ownership by Platform Ownership of data items may further be complicated by concepts defined in certain operating systems. Each operating system defines "p

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

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

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