Virtualisation has become an integral part of the modern computing landscape, allowing organisations to optimise their hardware resources and increase efficiency while reducing costs. 

At the heart of virtualisation technology lies the hypervisor, a software layer that enables the creation of virtual machines (VMs). 

In this article, we will look in-depth at what a hypervisor is, how it works, and the different types of hypervisors available.

What is Virtualization?

Virtualisation is creating a virtual version of a physical resource such as a server, desktop, operating system, storage device, or network. Virtualisation allows multiple virtual resources to share a single physical resource, thereby optimising the use of the hardware and increasing efficiency. Virtualisation can be applied to various resources, including servers, storage, networks, and applications.

The key benefit of virtualisation is the ability to create virtual machines (VMs), which are self-contained environments that emulate a complete computing system. Each VM has its virtual hardware, including CPU, memory, and storage, and runs its operating system. VMs can be created, cloned, and deleted quickly, making them a flexible and scalable solution for managing resources.

What is a Hypervisor?

A hypervisor, also known as a virtual machine monitor (VMM), is a layer of software that enables the creation and management of virtual machines. The hypervisor sits between the physical hardware and the virtual machines, managing the allocation of resources and ensuring that each VM runs independently of the others.

The hypervisor manages the allocation of physical resources such as CPU, memory, and storage to ensure each VM has the resources it needs to operate effectively. The hypervisor creates a virtualisation layer that abstracts the underlying hardware and presents it to the VMs as virtual hardware. The VMs interact with the virtual hardware as physical hardware, allowing them to run their operating systems and applications.

How does a Hypervisor work?

A hypervisor creates a layer of abstraction between the physical hardware and the virtual machines. The hypervisor presents a virtual view of the hardware to the VMs, which interact with it as physical hardware. The hypervisor also manages the allocation of physical resources to the VMs, ensuring each VM has the resources it needs to operate effectively.

Benefits of Virtualization with Hypervisors

Virtualisation with hypervisors offers several benefits to organisations, including:

• Better utilisation of hardware resources: Virtualization allows multiple virtual machines to share a single physical resource, optimising the use of hardware resources.
• Cost savings: Virtualization reduces hardware costs by allowing multiple virtual machines to share a single physical resource.
• Increased flexibility and scalability: Virtual machines can be created, cloned, and deleted quickly, making them a flexible and scalable solution for managing resources.
• Improved disaster recovery: Virtual machines can be backed up and replicated easily, making it easier to recover from disasters.
• Better security: Virtual machines are isolated from each other, providing better security than traditional physical servers.

Types of Hypervisors

There are two types of hypervisors: Type 1 and Type 2.

Type 1 hypervisors 

Type 1 hypervisors are designed for enterprise-level environments requiring high reliability, scalability, and security. They run directly on the host system's hardware and are not dependent on the host operating system.

Type 2 hypervisors 

Type 2 hypervisors are designed for desktop and laptop computers and are installed on top of an existing operating system. They are a cost-effective solution for creating virtual environments on desktop and laptop computers.

Examples of Type 1 Hypervisors

• VMware vSphere: VMware vSphere is a Type 1 hypervisor designed for enterprise-level environments. It provides a comprehensive virtualisation solution with management tools, high availability, and disaster recovery.
• Microsoft Hyper-V: Microsoft Hyper-V is a Type 1 hypervisor included with Windows Server. It provides a scalable virtualisation solution for enterprise-level environments.
• Citrix XenServer: Citrix XenServer is a Type 1 hypervisor that provides a virtualisation solution for data centres and cloud environments. It includes management tools, high availability, and disaster recovery.

Examples of Type 2 Hypervisors

• Oracle VirtualBox: Oracle VirtualBox is a Type 2 hypervisor for Windows, Mac, Linux, and Solaris. It provides a cost-effective solution for creating virtual environments on desktop and laptop computers.
• VMware Workstation: VMware Workstation is a Type 2 hypervisor for Windows and Linux. It provides a powerful virtualisation solution for developers and testers.
• Parallels Desktop: Parallels Desktop is a Type 2 hypervisor available for Mac. It provides a cost-effective solution for running Windows on a Mac.

FAQs

What is a hypervisor?

A hypervisor is a layer of software that enables the creation and management of virtual machines.

What are the benefits of virtualisation with hypervisors?

Virtualisation with hypervisors offers benefits such as better utilisation of hardware resources, cost savings, increased flexibility and scalability, improved disaster recovery, and better security.

What are the types of hypervisors?

There are two types of hypervisors: Type 1 and Type 2.

What is the difference between Type 1 and Type 2 hypervisors?

Type 1 hypervisors run directly on the host system's hardware, while Type 2 hypervisors are installed on top of an existing operating system.

What are some examples of hypervisors?

Examples of Type 1 hypervisors include VMware vSphere, Microsoft Hyper-V, and Citrix XenServer. Examples of Type 2 hypervisors include Oracle VirtualBox, VMware Workstation, and Parallels Desktop.

Can hypervisors run multiple operating systems on a single physical server?

Yes, hypervisors can create multiple virtual machines running different operating systems on a single physical server.

Is virtualisation with hypervisors only for large organisations?

No, virtualisation with hypervisors can be helpful for organisations of all sizes. Type 2 hypervisors, in particular, are a cost-effective solution for creating virtual environments on desktop and laptop computers.

Can hypervisors improve energy efficiency?

Yes, hypervisors can improve energy efficiency by enabling the consolidation of multiple virtual machines onto a single physical server, reducing the number of physical servers needed to run an organisation's IT infrastructure. This can result in lower energy consumption and reduced carbon footprint.