What is a Hypervisor?
In computing terms, a hypervisor, also called VMM or virtual machine manager, is amongst the different techniques used for hardware virtualization that allows multiple operating systems to run concurrently and use all the resources of a single machine. It appears that each of these operating systems have the memory, processor as well as other resources of the host only available to it. But, in reality, all the resources of the host are controlled by the hypervisor which manages to allocate the resources according the need of each of these operating systems. It also ensures that the guest (multiple OS) can’t disrupt the working of one another. Usually, the hypervisors are installed on the server machines and they can help in server consolidation along with expanding the hardware capabilities which allows every machine to handle more work simultaneously.
Hypervisor can be an ideal choice for cloud computing applications where you have to support various operating environments. It can make things virtualized very efficiently and quickly as well.
Hypervisors can be classified into two main types:
- Native hypervisors have the capability to run on the hardware of the host. They can more likely offer enhanced performance to all the users.
- Hosted hypervisors usually run as a distinct layer of software above the OS as well as the hardware. Such hypervisors are majorly used on the client systems for which efficiency is not very critical. They are also used on systems that need to support wide ranging I/O devices and host OS can provide this. Virtual Box, KVM are good examples of hosted hypervisors.