virtual box and its advantages,disadvantages and features

b)VirtualBox

It is an X86 virtualization package which is now maintained by Sun Microsystems.

Virtual Box is a powerful virtualization product for enterprise as well as home use.It is not only an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2.

Presently, Virtual Box runs on Windows, Linux, Macintosh, and Solaris hosts and supports a large number of guest operating systems.

Features of VirtualBox

Portability

 VirtualBox runs on a large number of 32-bit and 64-bit host operating systems To a very large degree, VirtualBox is functionally identical on all of the host platforms.It uses same file and image formats.This allows you to run virtual machines created on one host on another host with a different host operating system; for example, you can create a virtual machine on Windows and then run it under Linux.

No hardware virtualization required

 For many scenarios, VirtualBox does not require the processor features built into newer hardware like Intel VT-x or AMD-V. As opposed to many other virtualization solutions, you can therefore use VirtualBox even on older hardware where these features are not present.  

Guest Additions

 The VirtualBox Guest Additions are software packages which can be installed of supported inside guest systems to improve their performance and to provide additional integration and communication with the host system. After installing the Guest Additions, a virtual machine will support automatic adjustment of video resolutions,accelerated 3D graphics and more.  

Guest multiprocessing (SMP)

VirtualBox can present up to 32 virtual CPUs to each virtual machine, irrespective of how many CPU cores are physically present on your host.

USB device support

 VirtualBox implements a virtual USB controller and allows you to connect arbitrary USB devices to your virtual machines without having to install device-specific drivers on the host. USB support is not limited to certain device categories.

VM groups

 VirtualBox provides a groups feature that enables the user to organize virtual machines collectively, as well as individually. In addition to basic groups, it is also possible for any VM to be in more than one group, and for groups to be nested in a hierarchy. In general, the operations that can be performed on groups are the same as those that can be applied to individual VMs i.e. Start, Pause, Reset, Close.

Advantages of VirtualBox

·         Snapshots

·         64-bit

·         Shared folders

·         Special drivers and utilities to facilitate switching between systems

·         Command line interaction (in addition to the GUI)

Disadvantages of VirtualBox

o    Poor performance with 32-bit guests on AMD CPUs. This affects mainly Windows and Solaris guests, but possibly also some Linux kernel revisions. Partially solved in 3.0.6 for 32 bits Windows NT, 2000, XP and 2003 guests. Requires 3.0.6 or higher Guest Additions to be installed.

o    Mac OS X guests can only run on a certain host hardware.

o    VirtualBox does not provide Guest Additions for Mac OS X at this time.

o    There is no support for USB devices connected to Solaris 10 hosts.

o    No ACPI information (battery status, power source) is reported to the guest.

o    No support for using wireless adapters with bridged networking.

what is vmware. Advantages,disadvantages and features of vmware

                               a)Vmware

This is a platform where you will get everything on Virtual machine. Whether you need a virtual Datacenter, virtual server or desktop, you will get on vmware.

VMware's desktop software runs on Microsoft Windows, Linux, and Mac OS X.

Advantages of using VMware

• Cost effective use of hardware
• Large portions of your production environment can be replicated
on a few servers
• Lower cost of hardware for the entire test environment
• Faster rollback during testing
• Test VMs can be deleted after they are not needed

Disadvantages of using VMware

• Requires that your staff have some basic VMware
skills
• VMs are not good for load testing if your production environment
is completely physical

Features of VMware

Infrastructure services

The set of components that comprehensively virtualizes server, storage and network  resources, aggregate them and allocate them precisely on demand to applications based on business priority.

Application services

The set of components that provide built-in service level controls to all applications running on VMware, regardless of application type or operating system.

RAM over-commitment

Increase memory utilization by configuring virtual machine memory that safely exceeds the physical server memory. For example, the sum of the memory of all virtual machines running on a server with 8GB physical memory can be 16GB.

html code to show use of internal css

       Html code to show internal CSS

<html>

<head>

<style>

hr {color:red;}

p {margin-left:20px;}

body {background-color:green;font-size:30px;font-family:Times New Roman;}

</style>

</head>

<body>

<p>hi mca</p>

<hr>

</body>

</html>

Virtual,virtualization and virtual machine

 Virtual

Virtual means not real. The term virtual is popular among computer scientists and is used in a wide variety of situations. In general, it distinguishes something that is merely conceptual from something that has physical reality.

 Virtual (philosophy), A term used by Henri Bergson, Gilles Deleuze and Manuel DeLanda to denote potentiality as being equally real to actuality, but in a different manner.

For example: virtual memory refers to an imaginary set of locations, or addresses, where you can store data. It is imaginary in the sense that the memory area is not the same as the real physical memory composed of transistors.

·        Another analogy is the difference between the brain and the mind. The mind is a virtual brain. It exists conceptually, but the actual physical matter is the brain.

Virtualization

A computing technique to create representations of computer resources.

Virtual Machine

A virtual machine (VM) is a software program or operating system that not only exhibits the behavior of a separate computer, but is also capable of performing tasks such as running applications and programs like a separate computer. A virtual machine, usually known as a guest is created within another computing environment referred as a "host." Multiple virtual machines can exist within a single host at one time.

A virtual machine (VM) is a software implementation of a machine (e.g., a computer) that executes programs like a physical machine.

definition of www and definition of web browser

www 

Definition: The term WWW refers to the World Wide Web or simply the Web. The World Wide Web consists of all the public Web sites connected to the Internet worldwide, including the client devices (such as computers and cell phones) that access Web content. The WWW is just one of many applications of the Internet and computer networks.

The World Web is based on these technologies:

• HTML - Hypertext Markup Language
• HTTP - Hypertext Transfer Protocol
• Web servers and Web browsers

Researcher Tim Berners-Lee led the development of the original World Wide Web in the late 1980s and early 1990s. He helped build prototypes of the above Web technologies and coined the term "WWW." Web sites and Web browsing exploded in popularity during the mid-1990s.

Web Browser

The most common browser software titles on the market are: Microsoft Internet Explorer,Google's Chrome, Mozilla Firefox, Apple Computer's Safari, and Opera. Browser availability depends on the operating system your computer is using.

for example: Microsoft Windows, Linux, Ubuntu, Mac OS are different operating systems.

A browser is software that is used to access the internet. A browser lets you visit websites and do activities within them like login, view multimedia, link from one site to another, visit one page from another, print, send and receive email, among many other activities. 

installation of vmware

Installation  of  VMware
1.click on setup file of vmware.
2. Installation of vmware will get start
3.click next
4.select typical to get default settings.
5.here you can select the destination folder.click next.
6.if you want updates of product then select this option.click next.
7.You can give your feedback to vmware by selecting this option.click next.
8.If you want to create shortcuts on desktop and start then select these options.click next.
9.click continue to start installation.
10.click on finish as installation is complete.

Html code to show use of heading tag

Html code to show use of heading tag

<html>
<head>
<title>
hlo
</title>
</head>
<body>
<h1>hi</h1>
<h2>Subjects are</h2>
<h3>e-commerce and web applications</h3>
<h4>Data Mining</h4>
<h5>Graphics</h5>
<h6>Advanced operating System</h6>
</body>
</html>

C++ program to draw a line using putpixel

#include<iostream.h>
#include<conio.h>
#include<graphics.h>

main()
{
int gd=DETECT,gm,x2,y2;
float x1,y1,m,b;
initgraph(&gd,&gm,"C:\\turboc3\\bgi");
cout<<"enter starting points";
cin>>x1>>y1;
cout<<"enter ending points";
cin>>x2>>y2;
 m=(y2-y1)/(x2-x1);
b=y1-(m*x1);
if(m<1)
{
while(x1<=x2&&y1<=y2)
{
putpixel(x1,y1,WHITE);
x1=x1+1;
y1=(m*x1)+b;
}
}
if(m>1)
{
while(x1<=x2&&y1<=y2)
{
putpixel(x1,y1,WHITE);
y1=y1+1;
x1=(y1-b)/m;
}
}
getch();
closegraph();
}

C++ Program to rotate a line

/*Program to rotate a line*/
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
main()
{
int gd=DETECT,gm,x1,y1,a,b;
float sinth,costh,x2,y2;
initgraph(&gd,&gm,"c:\\turboc3\\bgi");
cout<<"enter line cordinates";
cin>>x1>>y1>>x2>>y2;
line(x1,y1,x2,y2);
cout<<"enter angle";
cin>>a;
costh=cos((3.14*a)/180);
sinth=sin((3.14*a)/180);
cout<<"enter 1 for anticlockwise or 0 for clockwise rotation";
cin>>b;
if(b==1)
{
x2=(x2*costh)-(y2*sinth);
y2=(x2*sinth)+(y2*costh);
line(x1,y1,x2,y2);
}
else
{
x2=(x2*costh)+(y2*sinth);
y2=(y2*costh)-(x2*sinth);
line(x1,y1,x2,y2);
}
getch();
closegraph();
}

program to move a circle in c++

/*Program to move a circle*/

#include<iostream.h>

#include<conio.h>

#include<graphics.h>

main()

{

int gd=DETECT,gm,x,y,a,b,c,d,r;

initgraph(&gd,&gm,"c:\\turboc3\\bgi");

cout<<"enter point cordinates";

cin>>x>>y;

cout<<”enter radius”;

cin>>r;

circle(x,y,r);

cout<<"enter translation  cordinates";

cin>>a>>b;

if(a>x)

{

x=x+a;

y=y+b;

circle(x,y,r);

}

else

{

x=x-a;

y=y-b;

circle(x,y,r);

}

getch();

closegraph();

}

what is multiprocessor system and types of multiprocessor sytem

Introduction

• A Multiprocessor system is system that has more than one processor on-board in the computer.They execute independent stream of instructions
• They share System buses.
• They share System clock.
• They share System Memory.
• They perform simultaneous process execution.
• They are Tightly coupled system.
• They can execute different processes at same time.

Models of Multiprocessor System

Symmetric

Asymmetric

model of multiprocessor system

Interconnection Networks of multiprocessor System

Bus:

• low cost
• one cpu-memory conversation at a time
• shared memory

Crossbar Switch:

• high cost.
• low expansion.
• CPU and memory units are connected to switch.

Multistage Network:

• compromise between bus and crossbar switch.
• Consists of many stages of 2*2 crossbar switches
• permits parllel conversations