What is Virtualization and its features?

The below information talks about the :
1. Introduction to Virtualization
2. Why to use it!
3. Types of Virtualization?

Virtulization means?:
Virtualization is virtualing the operating system, storage, devices servers like (HP, IBM, Dell and Citrix) or network resources.

It is very mush similar to the division of a hard drive into different partitions. A virtual partition is something like the logical division of a computer or storage hard disk drive to create, in effect, two separate hard drives.

Operating system(s) virtualization is the use of software to allow hardware(a piece of hardware) to run multiple operating system(s) images at the same time. Based on configuration VM machines will accupy space in your harddisk.

Virtualization is a combination of software and hardware engineering that creates Virtual Machines (VMs) - its an abstraction of the hardware that allows a single machine to act as many machines.
Without VM on the hardware:
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A single OS owns all hardware resources
With VM on the hardware:
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Multiple OSes, each running its own virtual machine, share hardware resources

Virtualization enables multiple operating systems to run on same physical hardware.

Why Virtualization:
Following are some representative reasons for and benefits of virtualization:

1. Virtual machines are used to consolidate the work-load of several under utilized server(s) to fewer machines, perhaps a single machine. Benefits are savings on hardware, environment cost, administration and management.

2. A legacy application might not run on newer hardware and operating systems. Even if it happens or does, if may under-utilize the server, so it makes sense to consolidating the several application(s). This may be difficult without virtualization as such an applications are not written to co-exist within a single environment.

3. Virtual machines allow perforamce monitoring, configuring harddisk properties and powerful debugging. Operating systems can be debugged without disturbing productivity, or setting up more complicated debugging scenario(s).

4. Virtual machines are excellent tool for research and experiment. Since they are good in providing isolation, they are safer to work with. They encapsulate the complete state of a running system, you can save state, examine, modify, reload.

5. It can enable the already existing Operating system to execute or run on shared memory.

6. Virtual machines can be used to create an arbitrary test set called scenarios, and can lead to very imaginative and effective quality assurance solution.

7. It can make task(s) like backup, recovery and migration easier and more manageable, which make very easy to maintain and rebuilt environment as and when required.

Types of Virtualization:

1. What is Storage Virtualization (SV):
It is a pool of physical storage from multiple network storage device(s) into (?) appears to be a single storage device and that is managed from a central console. SV is commonly used in storage area networks(SAN).

2. What is Network Virtualization (NV):-
NV is a way of combining the available resources in a network by splitting up the available bandwidth into channel(s), each of which is independent from the others resource, and also each of which can be assigned or reassigned to a particular server (or device) in real time. NV is intended to optimize reliability, flexibility, security, network speed and also scalability.

3. What is Server Virtualization (SV):-
Masking of server resource(s) which including the number and identity of individual processors, physical servers, operating systems) from server user(s). The main intention is to spare or isolate the user from having to understand and manage complicated and complex details of server resource(s), while increasing utilization, resource sharing and maintaining the capacity to expand it later(future use).