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

Cpu scheduling algorithm, Q. A CPU scheduling algorithm determined an orde...

Q. A CPU scheduling algorithm determined an order for the execution of its scheduled processes. Convinced n processes to be scheduled on one processor how numerous possible differ

Mention the various features that characteristics deadlock, Mention the var...

Mention the various features that characteristics the deadlock condition .  The four circumstances that give rise to deadlock condition are: 1) Mutual exclusion : As a minim

Define maintaining data on a per client basis, Define Maintaining Data on a...

Define Maintaining Data on a Per Client Basis Perhaps the most dramatic syntactical programming change for the application developer of client – server applications is maintain

Define a state which is not a fundamental process state, Define a state whi...

Define a state which is not a fundamental process state Answer: Blocked state is not a fundamental process state

Advanced synchronization, Synchronization serves two purposes: 1) to ensure...

Synchronization serves two purposes: 1) to ensure safety for updates on shared data (e.g. to avoid races conditions), and 2) to coordinate and order actions taken by threads (e.g.

Explain the thread local storage (tls), Explain the Thread Local Storage (T...

Explain the Thread Local Storage (TLS)    Windows NT provides unique functions for per-thread data management. Thread local storage (TLS) is a concept defined in NT so develope

Split the hexadecimal format, The following is a dump of a TCP header in h...

The following is a dump of a TCP header in hexadecimal format: 00CD0018 00000EF1 00000D5D 502200D1 01BF0010 We need to first split the above hex as such 00 CD 00 18 00 00

Explain lru second chance algorithm, Second chance Algorithm When the p...

Second chance Algorithm When the page is chosen the reference bit is checked to see whether it has been referenced before. If that is the case after that it is given a second c

Explain optimal page replacement, Optimal page replacement An optimal ...

Optimal page replacement An optimal page replacement algorithm has the least page fault rate of all algorithms. The algorithm states that a 'replace the page that will not be

Paging, Paging full question

Paging full question

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