Protection scheme in unix, Operating System

Assignment Help:

Q. Consider a system that holds 5000 users. Presume that you want to allow 4990 of these users to be able to access one file.

a. How would you denote this protection scheme in UNIX?

b. Could you propose another protection scheme that is able to be used more effectively for this purpose than the scheme provided by UNIX?

Answer:

a. There are two processes for achieving this:

1. Create an access control record with the names of all 4990 users.

2. Put these 4990 users in one group as well as set the group access accordingly. This scheme can't forever be implemented since user groups are restricted by the system.

b. The universal access to records applies to every user unless their name appears in the access-control list with different access permission. With this scheme you merely put the names of the remaining ten users in the access control list but with no access privileges allowed.


Related Discussions:- Protection scheme in unix

Write on short note dma., Write on short note DMA. Direct M emory...

Write on short note DMA. Direct M emory Access (DMA) is a technique for transferring data from  main to a device without passing it through the CPU. Computers that have

Explain fixed partitioning techniques, FIXED PARTITIONING In a fixed p...

FIXED PARTITIONING In a fixed partitioning, the operating system inhabiting some fixed portion of main memory is available for use of multiple processes -Using fixed partit

What is real time system, What is real time system? A real time system ...

What is real time system? A real time system has well explained, fixed time constraints. Processing must be done within the explained constraints, or the system will fail. It i

Implementation of locks, How could we implement locks? No matter how we cho...

How could we implement locks? No matter how we choose to implement them, we must have some hardware support. One possibility for implementing locks on a uniprocessor machine is is

Compression regarding the file system in windows 2000, Write short note on ...

Write short note on compression regarding the file system in Windows 2000. NTFS is able to perform data compression on individual files or on all data files in a directory. To

Explain the resource ownership and control, Explain the Resource Ownership ...

Explain the Resource Ownership and Control Operating systems are required to handle many different types of resources. CPU , memory, and I/O devices  are some of the varied sys

Pthreads, A thread is defined as an independent stream of instructions that...

A thread is defined as an independent stream of instructions that can be scheduled to run as such by the operating system. Each program contains a number of threads which can be ru

All the explanations of operating system and its types., operating systems ...

operating systems and its types together with its design issues and their examples.

Taxation problem, Smith, who is a civil engineer, purchased a 30-hectare bl...

Smith, who is a civil engineer, purchased a 30-hectare block of land in Australia in 1986 and used two hectares of it as a main residence. The part that was not main residence cost

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