Hypervisor and Virtualization

Hypervisor makes Virtualization possible.

What is Virtualization?

Virtualization - is a process where we have a single physical machine, and with the help of that single physical machine hardware, we run multiple virtual machines on top of that physical machine. All VM makes use of the hardware of the underlying physical machine.

Why do we go for Virtualization?

In layman's language, Virtualization helps us in making better use of our system hardware, as we can use our physical machine to its maximum potential. For eg - if you had a physical machine with 20 GB of RAM, but you were using it just for a small application (the app uses only 2 G.B RAM), the leftover RAM is just getting wasted. We can allocate more resources here and make full use of our physical machine by running other applications as well. With Virtualization, you also don't need to have physical hardware as well, as you can make use of borrowed hardware and pay for the usage time.

Some key points regarding Virtualization

cc: NextGenT(Youtube)

Hypervisor

A hypervisor is software that runs on a physical machine and virtualizes it. As we have seen above, we can use a single machine having RAM, CPU, and network to create more virtual machines that make use of the powers of the base physical compute host.

To achieve this, we make use of Hypervisor. Hypervisor sits on top of compute host and virtualizes the host machine parts. (CPU, RAM, Network).

Hypervisor allows us to schedule multiple virtual servers on top of it, creating a Virtual CPU, Virtual RAM, and virtual Network. As long as you don't run out of computing host processing power, you can create as many Virtual servers as you want.

Also, the Virtual servers that you create cannot interact with each other as the hypervisor makes sure of the security aspect as well.

Without hypervisors, one had to pay the full upfront cost for the whole computing system, but with virtualization, one can only pay for the resources used, turn it off when needed, and need not worry about scaling up or down.

Types of Hypervisor

1. Bare Metal Hypervisors

We install our hypervisor directly on the server. It means nothing is installed on the machine, the virtualization layer is installed directly on the bare metal server. Within that hypervisor, we can then add different virtual machines like Linux, windows, etc. This is what is commonly used in Datacenters. Generally, VMWare Hypervisors are running all over servers and are easily accessed by VMWare vSpher GUI.

cc: NextGenT(Youtube)

2. Hosted Hypervisors - A virtual desktop inside of an existing computer

Hosted Hypervisors are installed on our host OS, and in this case, you can run Virtual Machines from your own computer. You have a computer that is bare metal hardware and you have an O.S installed on top of it. We install our hypervisor directly below the host O.S and then we can create as many virtual machines as we need.

cc: NextGenT(Youtube)

E.g. - Oracle Virtual Box is a Type 2 Hypervisor