In virtualization, a single physical instance of
an application or resource is shared among multiple
organization or tenants
It does so by assigning a logical names to a
physical resources and providing a pointer to that physical resource when
Creating a virtual machine over existing
operating system and hardware is referred as Hardware Virtualization.
Virtual Machines provide an environment that is
logically separated from the underlying hardware.
The machine on which the virtual machine is
created is known as host machine and virtual machine is referred as a guest
This virtual machine is managed by a software or
firmware, which is known as hypervisor.
Hypervisor is a firmware or low-level program that acts as a
Virtual Machine Manager. There are
two types of hypervisor:
Type 1 hypervisor
runs on bare system. LynxSecure, RTS Hypervisor, Oracle VM, Sun xVM Server,
VirtualLogic VLX are examples of Type 1 hypervisor.
type1 hypervisor does not have any host operating system because they are
installed on a bare system.
Type 2 hypervisor
is a software interface that emulates the devices with which a system normally
interacts. Containers, KVM, Microsoft Hyper V, VMWare Fusion, Virtual Server
2005 R2, Windows Virtual PC and VMWare workstation 6.0 are examples of Type 2 hypervisor.
Type of Hardware Virtualization
There are mainly three types of hardware virtualization:
Here, the underlying hardware is completely simulated. Guest software does not
require any modification to run
Virtualization: In Emulation, the virtual machine simulates the hardware
and hence became independent of it. In this, the guest operating system does
not require modification.
In Para virtualization, the hardware is not simulated. The guest software run
their own isolated domains
vSphere is highly developed infrastructure that offers a management
infrastructure framework for virtualization. It virtualizes the system, storage
and networking hardware