Page 46 - DCAP103_Principle of operating system

Unit 1: Operating System

7. How do clustered systems differ from multiprocessor systems? What is required for two Notes
machines belonging to a cluster to cooperate to provide a highly available service?
8. How are network computers different from traditional personal computers? Describe some
usage scenarios in which it is advantageous to use network computers.
9. Give two reasons why caches are useful. What problems do they solve? What problems
do they cause? If a cache can be made as large as the device for which it is caching (for
instance, a cache as large as a disk), why not make it that large and eliminate the device?

10. Discuss, with examples, how the problem of maintaining coherence of cached data manifests
itself in the following processing environments:

( a) Single-processor systems
( b) Multiprocessor systems
( c) Distributed systems

11. Describe a mechanism for enforcing memory protection in order to prevent a program
from modifying the memory associated with other programs.

12. Define the essential properties of the following types of operating systems:
( a) Batch (b) Interactive (c) Time sharing
( d) Real time (e) Network (f) Parallel

( g) Distributed (h) Clustered (i) Handheld
13. What are the tradeoffs inherent in handheld computers?
14. What are the advantages and disadvantages of using the same systemcall interface for
manipulating both files and devices?
15. What is the purpose of the command interpreter? Why is it usually separate from the
kernel? Would it be possible for the user to develop a new command interpreter using
the system-call interface provided by the operating system?
16. Why is the separation of mechanism and policy desirable?
17. In what ways is the modular kernel approach similar to the layered approach? In what
ways does it differ from the layered approach?
18. What is the relationship between a guest operating system and a host operating system in
a system like VMware? What factors need to be considered in choosing the host operating
system?
19. Describe the actions taken by a kernel to context-switch between processes.
20. What is the main difficulty that a programmer must overcome in writing an operating
system for a real-time environment?
Answers to Self Assessment

1. operating system 2. user 3. control program 4. system call
5. (d) 6. (d) 7. (b) 8. (c)

9. (d)

LOVELY PROFESSIONAL UNIVERSITY 39