Hypervisor - General Information

A hypervisor is a software that allows you to create virtual machines and manage the resources they require. This software, also known as Virtual Machine Monitor (VMM), isolates the operating system and allocates CPU resources, memory, disk space, and networking components to the virtual machines created within the system. In this way, you can use a hypervisor to run multiple, different virtual machines with different operating systems in parallel on one host system, using the same hardware resources. 

The hypervisor also ensures that a virtual machine cannot access files of another virtual machine running in parallel. For example, this is important during software tests, so that other test environments cannot be affected by defective programs.

Type 1 Hypervisor

The first type of hypervisors are called bare metal hypervisors or native hypervisors. These hypervisors run directly on the host hardware to manage the virtual machines and are not connected to the host operating system. Therefore, such a hypervisor must also contain all necessary device drivers.

The bare metal hypervisor takes the place of the host operating system and retrieves resources directly from the hardware. The resource consumption of a type 1 hypervisor is relatively low.

Bare metal hypervisors are primarily used by users who want to create a server for virtualization. They are often used in corporate data centers or other server-based environments.

Examples of type 1 hypervisors include KVM and VMware vSphere.

Type 2 Hypervisor

The second type of hypervisor is also known as hosted hypervisor. This type of hypervisor is a software that runs as an application on an operating system. The hardware resources are scheduled against a host operating system, which is then executed against the hardware. 

A type 2 hypervisor is suitable for individual users who want to run multiple operating systems on one server or who want to use virtual machines for smaller projects.

Examples of type 2 hypervisors include VMware Workstation and Oracle VirtualBox.