A hypervisor refers to a piece of hardware, firmware, or application that makes virtualization possible. A computer that runs the hypervisor is referred to as the ‘host’ while resulting virtual machines are called ‘Guests’. Hypervisors separate physical components such as RAM from resulting virtual machines by creating virtualization layers.
Hypervisors are tasked with allocating and managing resources to guest machines. Hypervisors also make it possible for several operating systems to run simultaneously while using the same virtualized resources.
Some hypervisor vendors include Microsoft Hyper, VMware (most popular), Xen, and Kernel-based Virtual Machine (KVM).
How do Hypervisors Work
Hypervisors help in creating and managing Virtual Machines (VMs) by creating a layer between software and hardware. By translating requests from physical to virtual resources (CPU, RAM, and Storage) and vice versa, hypervisors make virtualization possible.
What are the two types of Hypervisors
There are two main types of hypervisors: Type 1 and Type 2.
Type 1 Hypervisor (Native/Bare Metal)
These types of hypervisors are installed directly on physical servers and the hardware underneath. The bare metal term comes from the fact that there is no operating system or software in between.
Because of their simplicity, they offer few functionalities compared to type 2 hypervisors.
Modern type 1 hypervisors include Microsoft Hyper-V, Oracle VM, POWER hypervisor, and Xbox One Systems software.
Type 2 Hypervisor (Hosted Hypervisors)
This type of hypervisor operates within an operating system that runs on a physical host server, hence the term hosted hypervisors. Hosted hypervisors are made of several components including:
- Physical server
- An operating system (Linux, Mac OS, or Windows)
- Type two hypervisors
- Guest virtual machine instances
Hosted hypervisors are convenient compared to type-1 hypervisors because they are easy to set up and manage. It is the best option for anyone who wants to run two different operating systems on the same computer.
The main benefits of using hypervisors are easy data replication, desktop virtualization, and server consolidation.