Question

Problem 3.1 Briefly answer the following questions on virtualization levels. Highlight the key points a the distinctions in different approaches. Discuss their relative advantages, shortcomings and limita- tions. Also identify example systems implemented at each level. nd identify

Please refer to the following textbook:

Distributed and Cloud Computing 1st edition

From Parallel Processing to the Internet of Things

ISBN:

0123858801

ISBN-13:

9780123858801

Authors:Kai Hwang Jack Dongarra Geoffrey Fox Geoffrey C Fox

Answer 1

Virtualization at different levels are as follows

A.Instruction Set Architecture level

All the machines has instruction set and which is in turn is an interface between the software and hardware. Virtualization at this level create an emulator which receives all the instruction from the virtual machine.

Example - When a virtual machine wants to use printer it then sends the instruction to the emulator.

b.Hardware Abstraction level

Hardware Abstraction Level is there to overcome the shortfall of the Instruction Set Architecture level. In this level the virtual resources are mapped with the physical resources. In this level all the instruction are not checked. Just it is checked if the instruction has privileged access or not. If it is there then it is passed Virtual Machine Monitor else it is not mapped.

c.Operating System level

Hardware Abstraction Level is good but it has a short come. If we want 500 virtual machines at once then Hardware Abstraction level will take a lot of time. So to overcome this Operating system level come into action. Here the os is shared between hardware and the virtual machine.

Example - 500 machines are there and we have to install different version of windows on each of it.What we will do is that install the base windows version to the machine and only different version will be there in different vm.

d.Programming Language level

Different application have different application user interface. So for supporting all type of API the programming language level virtualization used. Here Library interface is there to give Virtual environment for the application.

Example - For playing Counter Strike 1.6 in mac user uses WINE tool. At first the wine tool is available for the windows users only.

e.Applicaiton Layer Level

In application virtualization layer level virtual machines run as a particular in the Host machine. Particular layer is created for the Host machine and all the application are bundled with it.

Instruction Set Architecture level

Advantage

Here the virtual machine receives instruction to execute any certain hardware.

Disadvantage

Multiple instruction at once cannot be execute in the Instruction Set Architecture level

Hardware Abstraction level

Advantage

Here multiple instruction can be executed at once taking the instruction which have elevated access.

Disadvantage

The instruction which does not have privileged access are not mapped togethere.So this instruction are not executed.

Operating System level

Advantage

Installing software in multiple machines can be done at ease.

Disadvantage

Cost may rise up as multiple virtual machine are created for it,

Programming Language level

Advantage

Separate virtual environment is provided for different types of application to support their functionality.

Disadvantage

It takes up space for each VE is provided for all the different API's