Hypervisors - Type 1 vs Type 2

    Virtual machines have become an easy way to launch different operating systems for servers, testing, or exploring. Hypervisors serve as the software layer used to launch and manage guest operating systems on a host. Hypervisors are also sometimes referred to as virtual machine managers. Hypervisors come in two variations: type 1 and type 2.

    

    A type 1 hypervisor is installed directly onto a computer’s physical hardware. The lack of a host operating system allows type 1 hypervisors several benefits. Type 1 hypervisors boast high performance thanks to their ability to interact directly with the hardware. Type 1 hypervisors gain stronger security from no host operating system because of the smaller attack surface. While type 1 hypervisors are more secure and efficient, they can be complex to set up and run. Type 1 hypervisors are best suited for cloud and enterprise workloads due to their scalability and high performance. Examples of a type 1 hypervisor include VMware ESXi, Microsoft Hyper-V, and KVM.

                 

    A type 2 hypervisor performs the same function as a type 1 hypervisor but runs over a host operating system rather than just the hardware. Type 2 hypervisors are applications that can be downloaded to launch and manage virtual machines. Type 2 hypervisors are much simpler to configure and launch but come with a few drawbacks. Because type 2 hypervisors rely on the host operating system, they must share the physical hardware. This lowers the performance ability of type 2 hypervisors. Security of type 2 is also affected. Vulnerabilities from the host operating system are shared with the virtual machines. The presence of a host operating system also increases the system's attack surface, leaving it more exposed. Type 2 hypervisors are ideal for testing, development, and educational scenarios. Examples of type 2 hypervisors include VMware Workstation & Player, Oracle VirtualBox, and Parallels Desktop.