Basic CS-Operating System [TCS Placement]: Sample Questions 21 - 22 of 35

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Question 21

Operating System
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Describe in Detail

Essay▾

When is a system in safe state?

Explanation

  • If the system can allocate resources to the process in such a way that it can avoid deadlock- system is then in a safe state.
  • The set of dispatch able processes is in a safe state if there exists at least one temporal order in which all processes can be run to completion without resulting in a deadlock.
  • When a process requests an available resource, system must decide if immediate allocation leaves the system in a safe state.
  • System is in safe state if there exists a safe sequence of all processes.
  • A state is safe is the system can allocate resources to each process in some order and still avoids a deadlock.
  • More formally, a system is in a safe state only if there exists a safe sequence.
Given the Image is Defining the Example of Safe State

Question 22

Operating System

Describe in Detail

Essay▾

What are the stipulations of level security?

Explanation

C2 level security provides for:

Discretionary Access Control

  • Discretionary access control (DAC) is a type of security access control that grants or restricts object access via an access policy determined by an object՚s owner group and/or subjects.
  • DAC mechanism controls are defined by user identification with supplied credentials during authentication, such as username and password.
  • DACs are discretionary because the subject (owner) can transfer authenticated objects or information access to other users.
  • In other words, the owner determines object access privileges.
Given the Image is Define the Discretionary Access Control (DAC)

Identification and Authentication

  • Identification is the ability to identify uniquely a user of a system or an application that is running in the system.
  • Authentication is the ability to prove that a user or application is genuinely who that person or what that application claims to be.
  • For example, consider a user who logs on to a system by entering a user ID and password.
  • The system uses the user ID to identify the user.
  • The system authenticates the user at the time of logon by checking that the supplied password is correct.
Given the Image is Define the Identification and Authentication
  1. Auditing
    • A computer security audit is a manual or systematic measurable technical assessment of a system or application.
    • Manual assessments include interviewing staff, performing security vulnerability scans, reviewing application and operating system access controls, and analyzing physical access to the systems.
  2. Resource Reuse
    • Reusable resource a resource, such as a CPU or tape transport, that is not rendered useless by being used.
    • A magnetic disk or tape can be used often indefinitely and are to be regarded as reusable resources. Compare consumable resource.
Given the Image is Define the Reusable Resource Example

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