Brief History: 

Before we introduce and define Virtualization, we need to understand the origin of Virtualization. Before the rise of Virtualization, the Applications, and software run on a physical computer inside a Datacenter. Large Infrastructure running inside Datacenter introduced numerous challenges. The cost is a major factor that includes but not limited to Power, cabling, rack space, cooling, square foot area inside Datacenter for physical hardware, IT staff for management, etc. Also, in the Datacenter model, there is one to one mapping between the software and the computer. As a result, most of the systems are underutilized. Lastly setting up the infrastructure inside a Datacenter is a time-consuming process.

Introduction to Virtualization: 

Virtualization technology was a game-changer, it changed the entire perspective of how software should run inside a computer for enterprise organizations. As the name describes, virtual is not real but yet real. Below are the few types of Virtualization:

• Server Virtualization.
• Network Virtualization.
• Storage Virtualization.
• Desktop Virtualization.
• Application Virtualization.

The most important type we will talk about is Server Virtualization, it uses software called “Hypervisor” whose function is to emulate the underlying hardware (CPU, Memory, Storage, Network, etc.) and provide those resources to build a “Virtual Machine” (VM). Where we can install the OS (Operating System) of our choices like Windows, Linux, etc. It enabled us to create multiple VM’s on a single physical machine (hardware) and each VM has its resources like Memory, CPU, Network, Storage, OS, and application. The concept of Virtualization states that a single VM never fully utilizes underlying hardware. Hence it provides us higher flexibility, control, and isolation of the underlying hardware. The management of resources for a single VM is done by Hypervisor. Its Hypervisor responsibility to take resources from underlying physical hardware and pass those to VM’s and manage multiple VM’s.

Types of Hypervisor: 

There are two types of Hypervisor:

1. Bare Metal or Type 1 Hypervisor: When Hypervisor software is installed directly on the underlying hardware it’s called Bare Metal or Type1 Hypervisor. It consists of 3 layers (Hardware, Hypervisor, and VM). This technique provides excellent performance and improved stability. Examples include VMware ESXi, Citrix Xen, Microsoft Hyper-V, etc.
2. Hosted or Type 2 Hypervisor: When Hypervisor software is installed on top of an Operating System it’s called Hosted or Type2 Hypervisor. It consists of 4 layers (Hardware, OS, Hypervisor, and VM). Examples include VMware Workstation/Fusion, Oracle Virtual Box, etc.

Note: Type 1 Hypervisor is the de-facto standard for an enterprise organization.

Benefits of Virtualization:

Below are the benefits of Virtualization but are not limited to the following points only.

• Easy to build and manage Virtual machines.
• Each VM has its OS, Application thus enabling us to fully utilize the underlying hardware.
• It is cost-effective because multiple applications (VM’s) can be hosted on single hardware as compared to the Datacenter model.
• It is better for the environment because less hardware is procured which in turn reduces the amount of cooling and power supply requirements for the maintaining and running physical infrastructure.