When discussing technology with customers and coworkers, I often encounter confusion between virtualization and cloud computing.
“Aren’t they the same?” someone will ask.
The short answer is no. In fact, they differ in several respects.
Deploying virtualization in your data center doesn’t automatically mean you’re running a cloud. And it’s possible to deploy clouds without virtualization.
Let’s clear things up by looking at the main characteristics of each.
|Primary deliverable||Abstracted compute, network, & storage||Consumable services: Infrastructure (IaaS), Platform (PaaS), Software (SaaS)|
|Key value propositions||Improved utilization, rapid deployment||Commodity consumption model, increased agility, capacity on demand|
|Main customers||IT operations managers, systems administrators||Business application owners, developers, end-users|
|What to buy||Hypervisor & related tools||Services|
|How to deploy||Purchase and install in your facilities||Purchase from providers in a marketplace|
|Consumer interface||Computer operating system||Service Catalog|
|Units of capacity||System instances: CPU, memory, disk space, I/O||Compute cycles, bytes, & IOPS|
|Degree of difficulty||Quick to deploy on familiar infrastructure||Re-architect & replace|
|Cost implications||Significant capital outlay for hardware & software||Pay-as-you-go expense|
|Breadth of solutions||Relatively limited: VMware vSphere, Citrix Xen, Microsoft Hyper-V, other OpenSource||Thousands of vendor offerings|
|Degree of change||Evolutionary||Transformational|
So while the lines between virtualization and cloud are often blurry, they are essentially different.
They play at different levels of the application stack.
Virtualization is a foundational technology that makes IT infrastructure more flexible.
Clouds offer abstracted pieces and parts that can be assembled to deliver end-user services.
Clear or cloudy?