Computers

Question 1

What are the main os services?

Answer 1

∙ file management;
∙ input/output management;
∙ process management;
∙ memory management;
∙ multiprocessor management

Question 2

what does the kernelmode enable you to do?

Answer 2

switch from kernel tuser and use all of the computers functionality(priviliged instructions)

Question 3

what does the user mode enable you to do?

Answer 3

plain instructions

Question 4

What are the main possible os structures ?

Answer 4

monolithic;
layered;
microkernel;
modules

Question 5

Explain the monolitic os structure

Answer 5

has all services implemented by a large kernel. Examples: CP/M, MS-DOS.

Question 6

What problem might arise when a kernel has a monolithic

structure?

Answer 6

That there will be a large and disorganized mass of code , hard to understand and extend

Question 7

Explain the layered os structure

Answer 7

it has services
implemented by a large kernel, with a layered organisation.
Examples: UNIX, VMS.

Question 8

What problem might arise when a kernel has a layered structure ?

Answer 8

It wil be impossible to understand the design of the work as there will be ump layers and it will be diffiult to avoid flowing the wrong way

Question 9

What problem might arise when a kernel has a micro kernel structure ?

Answer 9

messanger failure
adn makes soving the problem longer which is not appropriate for grephics or network stransfers (high bandwiths huge data)

Question 10

Explain the micro kernel os structure

Answer 10

has services implemented by servers, and a small kernel delivering messages between them. Examples: Mach, QNX.

Question 11

Explain the modular os structure

Answer 11

It has services implemented by modules, and a small kernel that loads them on demand. Examples: Linux, OS X

Question 12

What are the stages of the bootstrap?

Answer 12

the stage one boot loader is run from BIOS ROM;
the stage two boot loader is loaded from disk and run;
the operating system proper is loaded from disk and run.

Question 13

What does a virtual machine do ?

Answer 13

A virtual machine abstracts a physical computer into a virtual one. Examples: VMware, VirtualBox

Question 14

what are dual boots or tri boots usually used for?

Answer 14

Virtual Machines