Virtualization

Virtualization

In computing, virtualization is a broad term that refers to the abstraction of computer resources.

Virtualization effectively ‘hides’ the physical characteristics of computing resources from the way in which other systems, applications, or end users interact with those resources. Thus, a single physical resource [ server, OS, application, or storage device] appear to function as multiple logical resources, or it can include making multiple physical resources [storage devices or servers] appear as a single logical resource.

Virtualization can also include making one physical resource to appear, with somewhat different characteristics, as one logical resource.

The term is applied to many different aspects of computing- from entire networks to individual capabilities or components. The common theme of all virtualization technologies is the ‘hiding of technical detail’, through encapsulation.

Virtualization creates an external interface that hides an underlying implementation (e.g., by multiplexing access, by combining resources at different physical locations, or by simplifying a control system). Recent development of new virtualization platforms and technologies has refocused attention on this mature concept.

Types of Virtualization

Virtualization is used in many different contexts, however these can be logically grouped into two main types:

1. Platform virtualization - the simulation of whole computers
2. Resource virtualization - the simulation of combined, fragmented, or simplified resources

Platform Virtualization

Platform virtualization is performed on a given hardware platform by host software [a control program], which creates a simulated computer environment, a virtual machine, for its guest software.

The guest software, which is often itself a complete operating system, runs just as if it were installed on a stand-alone hardware platform.

Typically, many such virtual machines are simulated on a single physical machine, their number limited only by the host’s hardware resources.

Typically there is no requirement for a guest OS to be the same as the host one. The guest system often requires access to specific peripheral devices to function, so the simulation must support the guest's interfaces to those devices.

NEXT: Uses For Virtualization

Back To Top