Teodor Wisniewski
May 18

Virtualization: Key Concepts and Applications

Notes on Virtualization

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Virtualization, a buzzword in today's tech world, has transformed the way we perceive and interact with computer hardware. To comprehend the concept better, let's dive deep into its meaning, origin, benefits, and various use-cases.

What is Virtualization?

In its simplest form, virtualization makes one physical computer act like many computers. It's a technology that allows you to create multiple simulated environments or dedicated resources from a single, physical hardware system. The term "virtualization" traces its roots back to the 1960s when IBM introduced a method to logically partition mainframe computers into separate 'virtual' machines.

The Origins and Etymology of 'Virtualization'

The term 'virtualization' has its origins in the realm of computing, specifically with the advent of mainframe computers. It was first introduced by IBM in the 1960s to logically partition mainframe computers into separate 'virtual' machines, allowing them to run multiple applications and processes simultaneously.

The word 'virtual' itself derives from the Latin 'virtus' meaning 'excellence' or 'potency'. In the context of computing, 'virtual' was initially used to refer to something that wasn't physically present but made to appear so by software.

Thus, 'virtualization' essentially refers to the act of creating a virtual version of something, including but not limited to a hardware platform, operating system, a storage device, or network resources.

Why Do We Virtualize?

The motivation behind virtualization is manifold. With the ever-growing digital world, there's an increased need for server capacity. However, setting up and maintaining a multitude of physical servers isn't cost-effective or environmentally friendly. This is where virtualization steps in, offering a more efficient and resourceful solution.

The Role of Hypervisor Software

The linchpin of virtualization technology is hypervisor software. Acting as a go-between, the hypervisor connects the physical server and the virtual machines, managing resource allocation so each virtual machine operates independently of each other.

The Benefits of Virtualization

Virtualization comes with an array of benefits, which include:

  1. Quick Updates: Virtual environments allow for quick and easy system updates without impacting the physical server.
  2. Disaster Recovery: Virtual machines can be saved as files, enabling efficient recovery in case of system failure.
  3. Cost Savings: Fewer physical servers mean reduced hardware and energy costs.
  4. Agility and Speed: Virtualization allows for faster system setup and scaling.
  5. Lower Downtime: With the ability to migrate virtual machines, system downtime can be significantly reduced.
  6. Flexibility: Virtual machines can easily be moved, copied, and reassigned between hardware hosts.
  7. Sandboxing and Testing: Virtualization enables testing and experimenting in a separate, secure environment, without risking the primary system.

Virtualization Use Cases

Virtualization finds its application in various domains:

  1. Physical to Virtual Migrations: It allows for seamless migration from a physical server to a virtual environment.
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  1. Virtual Desktop Infrastructure (VDI): In VDI, the user's desktop inside a virtual machine resides on a server in the data center.
  2. Data Center and Cloud: Virtualization forms the core of cloud computing, providing scalability, quick provisioning, and cost savings. It allows for a smaller footprint compared to maintaining one's own infrastructure.

Understanding 'Footprint' in the Context of Virtualization

In virtualization, 'footprint' typically refers to the amount of physical resources - like storage space, RAM, or CPU capacity - that a virtual machine uses on its host server. The smaller the footprint, the less impact the virtual machine has on the host's resources, allowing for more efficient use of hardware.

Types of Virtualization: Type 1 and Type 2

Virtualization can broadly be classified into two types - Type 1 and Type 2, each serving distinct purposes and use-cases.

Type 1 Virtualization

Also known as 'bare metal' or 'native' virtualization, Type 1 hypervisors run directly on the host's hardware to control the hardware and to manage guest operating systems. This makes them extremely efficient, offering high performance and stability. They are predominantly used in enterprise environments where managing multiple servers efficiently is critical. Examples of Type 1 hypervisors include VMware ESXi, Microsoft Hyper-V, and Xen.

Type 2 Virtualization

Contrarily, Type 2 hypervisors, also known as 'hosted' hypervisors, run on a conventional operating system just as other applications on the system do. A Type 2 hypervisor abstracts guest operating systems from the host operating system. While this type may not provide the same level of performance as Type 1, it's more flexible, allowing for a broader range of hardware compatibility. VMware Workstation, Oracle VirtualBox, and Parallels Desktop are examples of Type 2 hypervisors.


The journey of understanding virtualization reveals its sheer significance in modern computing. By reducing costs, increasing efficiency, and providing flexibility, virtualization is truly redefining our approach to computing infrastructure.