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

Why high level languages need compiler, Q. Why High level languages need Co...

Q. Why High level languages need Compiler? High level languages - illustrations are COBOL, FORTRAN, PL/I andALGOL - are processed by interpreters andcompilers. A compilers is a

What is an acyclic graph, What is an acyclic graph? A tree that has bee...

What is an acyclic graph? A tree that has been corrupted by links to other branches, but does not have any cyclic paths in it.

Thread pools, Another solution then would be to keep a pool of threads. Whe...

Another solution then would be to keep a pool of threads. Whenever a new task arrives, the system would simply get a thread from pool and set that thread to work on the given task.

Define i/o and cpu bursts, Define I/O and CPU Bursts   Applications typ...

Define I/O and CPU Bursts   Applications typically to through cycle of CPU bursts and Input/output bursts. Since the CPU sits idle during I/O operations, efficiency is improved

Peripharal device, 50 peripharal device name ,diagram and uses

50 peripharal device name ,diagram and uses

Determine the requiring variables on the scope of a thread, Determine the R...

Determine the Requiring Variables on the Scope of a Thread It is very common in server application programs to require variables on the scope of a thread. To provide such a sco

What is cold backup, Cold Backup: It is copying the three groups of files...

Cold Backup: It is copying the three groups of files when the object is shut down. This is a straight file copy, generally from the storage disk directly to tape. You must end th

Determine the minimum number of units of resource, An operating system invo...

An operating system involves 3 user processes each one requiring 2 units of resource R .The minimum number of units of R like no deadlocks will ever take place is The minimum

Write knowledge base relevant propositional statement, Suppose a logic-base...

Suppose a logic-based agent in the wumpus world has found that locations (1,1) and (2,1) do not contain a stench, but that locations (3,1) and (2,2) do contain a stench. Can the ag

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