Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
1. On every access, mark the page with a timestamp. Whenever we need to evict a page, we search through memory for the oldest page, the least-recently used page. But we need memory
What is internal fragmentation? Consider holes of 20k assume the process requests 18 bites. If we allocate accurately the request block, we are left with a hole of 2k. The over
Q. What are the three main activities of an operating system in regard to secondary-storage management? Answer: 1) Free-space management 2) Storage allocation 3) Disk
Explain the basic method of paging method. Physical memory is divided into the fixed-sized blocks called frames. Logical memory is as well divided into blocks of the same size
Question: a) Illustrate with the help of a diagram, the difference between two tier and three tier architectures. b) Explain in what kind of environment, a peer to peer envi
What is a thread? A thread or else called a lightweight process (LWP) is a basic unit of CPU utilization, it comprises of a thread id, a program counter, a register set and a s
What is a semaphore? A semaphore 'S' is a synchronization tool which is an integer value that, apart from initialization, is accessed only by two standard atomic operations; w
Question 1 Discuss the following with respect to Operating Systems: Operating System Components Operating System Services Question 2 Describe the theory behind Pagin
What are the operations of processes? Process creation A process may create several new processes. The creating process is called as parent process, where as the new proce
Define FIFO Page Replacement Algorithm This policy simply eliminates pages in the order they arrived in the main memory. By using this policy we simply remove a page based upo
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd