Why to Use server virtualization (SV) technology?

Well, the main driving force behind server virtualization is "SERVER CONSOLIDATION".
The other reasons for implementing server virtualization are
Redundancy, Migration, & Legacy systems..

Let's look into consolidation.. :-)
Server virtualization conserves space through consolidation. It's common practice to dedicate each server to a single application. If several applications only use a small amount of processing power, the network administrator can consolidate several machines into one server running multiple virtual environments. For companies that have hundreds or thousands of servers, the need for physical space can decrease significantly.

AND interestingly, Consolidation Fills our pocket..

Wanna See how drastically it reduces the investment on servers?

HERE WE GO >>>>>>>>>>>>>>>
Here's the cost table before consolidation


click on image to have a larger view


Here's the cost table After consolidation


click on image to have a larger view

Field of Virtual Hardware...

Well, this one is interesting challenge to the system hardware contributors...!
i,e.. giving us the ready made Virtual Hardware ...
this might be a bugging issue "why to look for virtual hardware and what it is.."
and the answer is quite uncomplicated...
instead of virutalizing the system using a software and utilizing the layer called "Hypervisor".. virtual hardware provides a mechanism of inbuilt virtualization.. means the hardware components have in-built capacity of supporting virtualization.. it doesn't mean that we do not have to use virtualization software to realize the mechanism. instead hardware has got inbuilt hypervisor.. but one should keep in mind that WE DO HAVE TO USE A SOFTWARE TO INITIALIZE THE VIRTUALIZATION MECHANISM.
By this virtual hardware system we can have improvement over the resource utilization.

In 1990's INTEL and AMD companies offered virtual hardware surprisingly at the same period of time.. but they both have different architectures and algorithms of achieving virtualization..

How to create a virtual server?

That's the baffling question for creating a virtual server...
and all in all there are 3 ways of creating a Virtual Server..
1) Full paralization
2) Para virtualization
3) OS level virtualization..

i) Full virtualization:

Full virtualization uses a special kind of software called a hypervisor. The hypervisor interacts directly with the physical server's CPU and disk space.
It serves as a platform for the virtual servers operating systems.
The hypervisor keeps each virtual server completely independent and unaware of the other virtual servers running on the physical machine.
Each guest server runs on its own OS -- you can even have one guest running on Linux and another on Windows.



ii) para-virtualization :



The para-virtualization approach is a little different. Unlike the full virtualization technique, the guest servers in a para-virtualization system are aware of one another. A para-virtualization hypervisor doesn't need as much processing power to manage the guest operating systems, because each OS is already aware of the demands the other operating systems are placing on the physical server. The entire system works together as a cohesive unit.



iii) OS level virtualization :


An OS-level virtualization approach doesn't use a hypervisor at all. Instead, the virtualization capability is part of the host OS, which performs all the functions of a fully virtualized hypervisor. The biggest limitation of this approach is that all the guest servers must run the same OS. Each virtual server remains independent from all the others, but you can't mix and match operating systems among them. Because all the guest operating systems must be the same, this is called a homogeneous environment. What OS-level virtualization loses is in terms of flexibility, it gains in native-speed performance.






HERE'S THE VIDEO TO VISUALIZE THE DIFFERENT WAYS OF VIRTUAL SERVERS.... :-) :-)

What exactly server virtualization is all about?

Server computersare machines that host files and applications on computer networks and have to be powerful. Some have central processing units (CPUs) with multiple processors that give these servers the ability to run complex tasks with ease. Computer network administrators usually dedicate each server to a specific application or task. Many of these tasks don't play well with others -- each needs its own dedicated machine. One application per server also makes it easier to track down problems as they arise. It's a simple way to streamline a computer network from a technical standpoint.
There are a couple of problems with this approach, though. One is that it doesn't take advantage of modern server computers' processing power.
Most servers use only a small fraction of their overall processing capabilities.
Another problem is that as a computer network gets larger and more complex, the servers begin to take up a lot of physical space. A data center might become overcrowded with racks of servers consuming a lot of power and generating heat.


Server virtualization attempts to address both of these issues in one fell swoop. By using specially designed software, an administrator can convert one physical server into multiple virtual machines. Each virtual server acts like a unique physical device, capable of running its own operating system (OS). In theory, you could create enough virtual servers to use all of a machine's processing power, though in practice that's not always the best idea.