Introduction to Virtualisation: What Is a Hypervisor?

Virtualisation technology makes it possible to separate hardware resources like CPU and storage from physical computers. Most famously, it’s the foundation of cloud computing. Hypervisors play a key role in the process of virtualisation. The following article explores hypervisor use cases, types, benefits, and disadvantages. 

What is a hypervisor?

A hypervisor is a thin virtual machine monitor (VMM) software layer. Before their existence, most computers could only run one operating system (OS) at a time. With a hypervisor, you can run multiple operating systems using one host machine. This practice helps reduce the waste of computational resources. 

What is the primary function of a hypervisor?

Hypervisors separate a system's operating system (OS) and resources from the physical machine. They organise these separated resources into files called virtual machines (VMs). Then, they assign computing power, data, and storage to each one. A hypervisor prohibits the files from interfering with one another, thereby maintaining the system. 

Types of hypervisors

Type 1 hypervisor

A type 1 hypervisor is sometimes called a native hypervisor or a bare-metal hypervisor. Its pseudonyms are derived from the method of installation. Bare-metal hypervisors are installed and run directly on the physical hardware of a computer.

Pro: Programs and software typically go through an OS layer to reach hardware resources like CPU and memory. Since a type 1 hypervisor has direct access to the physical computer, it's fast, secure, and efficient. 

Con: Type 1 hypervisors may require a dedicated machine separate from the host hardware. This secondary machine is needed to instruct the virtual machines and control hardware resources. 

Type 2 hypervisor

Type 2 hypervisors run like applications through the OS of the physical machine. This type of hypervisor is also known as an embedded hypervisor or a hosted hypervisor. Unlike type 1 hypervisors, hosted hypervisors don't have direct access to the underlying hardware. They must go through the hardware's OS to interact with its physical resources. 

Pro: Type 2 hypervisor setup is quicker and easier because operating systems are more user-friendly. 

Con: Latency issues such as lagging are more common among type 2 hypervisors. They also tend to need to be more secure. Both of these issues exist because hosted hypervisors must access hardware resources indirectly through an OS. If the hardware's OS is compromised, the OS of any virtual machines the hypervisor has created will be compromised, too. 

What is a hypervisor used for?

It is unlikely that a single OS would occupy all of a computer's resources. However, multiple operating systems running alongside each other (VMs) can. Hypervisor technology allows more use of a system's available resources. They save space and maintenance by creating independent operating systems that share the resources of a single machine.

What is the difference between a hypervisor and a virtual machine?

Virtual machines are files that recreate the computing environment of a physical computer. A hypervisor is software that runs these files. Hypervisors allocate hardware resources to virtual machines and ensure they remain independent from one another, thereby maintaining the system. An excellent way to conceptualise the relationship between the two is to imagine hypervisors as the platform virtual machines must operate. 

How to work with hypervisors

Occupations that work with hypervisors and virtualisation belong to the computer and information technology field. If you want to land a job in computer and information technology, consider obtaining a qualification in a relevant area. Advanced careers in this field may require a graduate degree. Several relevant master’s degrees are offered on Coursera, such as the Master of Computer and Information Technology and a Master of Engineering in Engineering Management degrees offered by top Universities. 

Career paths in virtualisation 

The list below outlines a couple of positions that may work closely with virtualisation technology:

• Systems engineer: Many system engineers work with hypervisors. Their primary responsibility is overseeing computer systems engineering, management, and security. For this reason, systems engineers should have excellent project management and problem-solving skills. The average total pay for a systems engineer in India is ₹8,12,300 annually [1]. 

• Virtualisation engineer: Virtual engineers specialise in managing virtual computing platforms. Their duties include migration management, end-user troubleshooting, and the maintenance of hypervisors and virtual machines. Virtualisation engineers must stay current on virtualisation trends and technologies. Professional Certificates in relevant fields of study can be highly beneficial for this position. The annual base pay for virtualisation engineers in India is ₹7,60,000 [2].

You can learn more about operating systems and build your skill set with an online course like Introduction to Operating Systems 1: Virtualisation.

Getting started with Coursera

By taking an online course, Specialisation, or Professional Certificate on Coursera, build a deeper understanding of hypervisors and virtualisation. To learn more about network virtualisation and boost your resume, consider earning a shareable certificate, such as the one gained in Georgia Tech’s Network Function Virtualisation.