Hypervisor , also
known as a hypervisor Virtual Machine Monitor (VMM).
A hypervisor is computer software or firmware on
which virtual Machin runs
There
is two types of Hypervisor. Type 1 and Type 2.
Type 1 hypervisor:
hypervisors run directly on the system hardware – A “bare metal” embedded
hypervisor,
means
that it has direct access to the hardware.
The hypervisor is small as its main task is sharing and managing hardware resources between different operating systems.
Type 1 hypervisors are gaining popularity because building the hypervisor into the firmware is proving to be more efficient. According to IBM, Type 1 hypervisors provide higher performance, availability, and security.
A major advantage is that any problems in one virtual machine or guest operating system do not affect the other guest operating systems running on the hypervisor.
Example
: Xen, Microsoft
Hyper-V, VMware
ESX and ESXi
Type
2 hypervisor: hypervisors run on a host operating system that provides
virtualization services, such as I/O device support and memory management.
In this case, the
hypervisor is installed on an operating system and then supports
other operating systems above it.
It
is completely dependent on host Operating System for its operations.
While having a base
operating system allows better specification of policies, any problems in the
base operating system a ffects the entire system as well even if the hypervisor
running above the base OS is secure.
Type 2 hypervisors
be used mainly on client systems where efficiency is less critical or on
systems where support for a broad range of I/O devices is important and can be
provided by the host operating system.
Example KVM, VMware
Workstation/Fusion/Player, Microsoft Virtual
PC, Oracle Virtual Box
