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

Android operating system, Android operating system is an open source, Linux...

Android operating system is an open source, Linux-based Smartphone OS. It is the world's most popular mobile platform with more than 700,000 applications and 25 billion downlo

Explain many-to-one model (green threads), Many-to-One Model (Green Threads...

Many-to-One Model (Green Threads) Implementations of the many-to-one model a lot of user threads to one kernel thread permit the application to create any number of threads tha

Mechanism for code and data sharing, Q. Consider a system in which a progr...

Q. Consider a system in which a program is able to be separated into two parts: code and data. The CPU recognizes whether it wants an instruction (instruction fetch) or data (data

Deadlock, Suppose we have 3 processes running at the same time as shown in ...

Suppose we have 3 processes running at the same time as shown in the following table. Each resource only has one instance. Show a possible scenario of resource allocation that r

Define page stealing, Define Page stealing    Page stealing is taking ...

Define Page stealing    Page stealing is taking page frames another working sets

Definition of operating system, Q. Definition of Operating System? Defi...

Q. Definition of Operating System? Definition of Operating System: • An Operating system is a program which controls execution of application programs and acts as an interfa

Explain the alphabet and string, Explain the Alphabet and String A fini...

Explain the Alphabet and String A finite set of symbols is known as alphabet. An alphabet is frequently denoted by sigma, yet can be given any name. B = {0, 1} says B is an

Quick, why we say " OS is a resource allocator" and “OS is a control progr...

why we say " OS is a resource allocator" and “OS is a control program"?

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