How to Use a Hypervisor in Cloud Computing Virtualization - dummies

How to Use a Hypervisor in Cloud Computing Virtualization

By Judith Hurwitz, Robin Bloor, Marcia Kaufman, Fern Halper

A hypervisor is an operating system, which means that it knows how to act as a traffic cop to make things happen in an orderly manner. The hypervisor sits at the lowest levels of the hardware environment. Because in cloud computing you need to support many different operating environments, the hypervisor becomes an ideal delivery mechanism.

The hypervisor lets you show the same application on lots of systems without having to physically copy that application onto each system. One twist: Because of the hypervisor architecture, it can load any (or many) different operating system as though it were just another application. Therefore, the hypervisor is a very practical way of getting things virtualized quickly and efficiently.

Scheduling access with the hypervisor

You should understand the nature of the hypervisor. It’s designed like a mainframe OS rather than like the Windows operating system. The hypervisor therefore schedules the amount of access that guest OSes have to everything from the CPU; to memory; to disk I/O; and to any other I/O mechanisms. With virtualization technology, you can set up the hypervisor to split the physical computer’s resources. Resources can be split 50-50 or 80-20 between two guest OSes, for example. Without the hypervisor, you simply can’t do that with Windows.

The beauty of this arrangement is that the hypervisor does all the heavy lifting. The guest operating system doesn’t care (or have any idea) that it’s running in a virtual partition; it thinks that it has a computer all to itself.

Defining types of hypervisors in cloud computing

Different hypervisors support different aspects of the cloud. Hypervisors come in several types:

  • Native hypervisors, which sit directly on the hardware platform are most likely used to gain better performance for individual users.

  • Embedded hypervisors are integrated into a processor on a separate chip. Using this type of hypervisor is how a service provider gains performance improvements.

  • Hosted hypervisors run as a distinct software layer above both the hardware and the OS. This type of hypervisor is useful both in private and public clouds to gain performance improvements.