Virtualization in Operating System

In computing, virtualization means to create a virtual version of a device or resource, such as a server, storage device, network or even an operating system where the framework divides the resource into one or more execution environments.

In simple, virtualization deals with extending an existing interface so as to mimic of another system.

Examples. virtual private network, virtual machine, virtual memory, etc.

Let us compare the physical machine and virtual machine,

Physical machine:

Fig. Physical Machine Architecture.

Here, new term is NIC.

What is NIC ?

NIC stands for “Network Interface Controller”.

NIC controls the wired or wireless connections of a computer system to exchange the information with another computer system and the internet.

Now, let us see about the virtual machine.

Fig. Virtual Machine Architecture

In virtual machine architecture, the Operating system layer in physical machine is replaced with virtualization layer.

Virtual systems are used to increase the use of CPU. As in physical system many times the CPU is idle. Virtual machine improves the utilization of CPU.

Virtual system isolation — Virtual systems are isolated from one another. One virtual system can’t affect another virtual system. For ex. viruses present in one virtual environment can’t affect another virtual environment.

Drawbacks

In virtual system , to perform certain operation in which for ex. CPU is involved then virtually created CPU of M/C calls actual CPU to perform operation. So the delay to perform certain operation is sometimes more as it is one of the drawback.