What’s the Difference Between Virtualization and Cloud Computing?
While virtualization and cloud computing might share a common bond, there is a difference between them and it’s important to understand what that difference is.
One common misconception I routinely notice when talking with people about technology is the idea that virtualization and cloud computing are the same thing. It’s not impossible to see where this conclusion stems from, given the influx of overwhelming information concerning both concepts. While these technologies might share a common bond of maximizing computing resources, there is a difference between them and it’s important to understand what that difference is.
Virtualization in a nutshell
To put it simply, virtualization is the process of simulating “virtual” versions of infrastructure resources, such as computing environments, operating systems, storage devices or network components, as opposed to creating actual or physical versions of those same resources. For example, you have a physical server (the “host”) that controls all of its physical resources (the operating system, memory, storage, etc.) – those resources can be allocated to virtual machines (“VM”s) that run in containers provided by that host. Virtualization enables multiple instances of infrastructure resources to run on the same hardware, with access to those resources being controlled by a hypervisor (I’ll get to that in a second.) Take a look at the picture below.
A hypervisor, also referred to as a virtual machine manager (“VMM”), is the software layer that controls access to the host’s physical hardware, and creates and runs the VMs. There are two types of hypervisors: bare metal/native or hosted. In a bare metal instance, the hypervisor runs directly on the host’s hardware and allows running multiple operating systems on the same physical hardware. Hosted hypervisors run on top of the host’s operating system, and additional operating system environments are run within the host’s OS. In a nutshell, bare metal hypervisors run directly on hardware while hosted hypervisors run on top of an operating system such as Windows or Linux.
That’s great…but where does the cloud come in?
Cloud computing is the delivery of shared computing resources, software or data as a service via the Internet, as opposed to virtualization, which is part of a physical infrastructure. For users of either technology, it may appear that the two are one in the same, as the applications or data they’re accessing are pulled from a virtual machine somewhere unconnected to a physical host. That’s partly where some of the confusion happens.
Cloud computing is built on top of a virtualized infrastructure, consisting of compute, storage and network components. There are a variety of different service models that represent cloud computing, such as SaaS, IaaS, and PaaS (I’ll cover these in a later post), and there are many key characteristics that define the “cloud”, such as agility, scalability, automation, and on-demand service delivery.
So there you have it
By itself, virtualization can reduce complexity for end users while allowing an organization’s IT resources to be utilized more effectively. But cloud computing takes the use of those resources to the next level by delivering access to those components on-demand as a service, further reducing complexity, cost and burden. Essentially, virtualization is a logical action for businesses to take when considering the adoption of a cloud computing strategy.
by Heather Boothe, Virtual Command Operations