Where Does Virtualization End and Cloud Begin

There’s much heated debate over cloud computing. The fact is that cloud computing is a paradigm shift in how we deliver compute capacity to end users. Virtualization, on the other hand, while enabling many of the conveniences of cloud computing, is not required to actually build a cloud. Virtualization, also, is an actual technology that creates a paradigm shift, not just a label for a paradigm shift, itself, like cloud computing is. In other words, there is no product that can “cloud you”, while there are many products that can “virtualize your business.” That said, most well-designed clouds include virtualization technologies.

The virtualization technologies that help enable cloud computing paradigms include virtualized networks, virtualized storage, virtualized name spaces, IP addresses, and clustered resources; and probably the mostly referred to, virtualized server and desktop machines. I’ll assume, at this point, if you’re reading this, you’re familiar with virtualization as it generally pertains to servers and desktops.

The question is, where does virtualization end and cloud begin?

To answer that, we have to establish some generally agreed assertions about cloud computing. In general, a modern cloud infrastructure will provide at least:

  • Self-Service – A self-service user portal to deploy and destroy compute instances
  • Automation and Elasticity – An engine that automatically handles the deployment request, notifies the user when the resource is ready, and terminates the resource when the user indicates it is no longer needed
  • Metering and Reporting – An administrative tool that meters the consumption of resources in the cloud as well as the ability to report on that usage, these two may be separate or an integrated solution
  • Billing & Charge-back (optional) – Depending on whether the cloud is designed for monetary gain or for organizationally charged back resources, the cloud may have the ability to do automated billing and/or automated charge-back

While there may or may not be dozens or hundreds of additional attributes to any given cloud infrastructure, I think that most cloud architects would agree that the above list is relatively inclusive of the basic components of an Infrastructure as a Service (IaaS) cloud solution.

In general, I have seen two marketectural (Marketing and Architecture) approaches to the answer to our question.

The first approach seems to treat virtualization as a very traditional component of cloud computing. The virtualization component of the cloud simply virtualizes servers and desktops and provides access to storage and networking for them. This approach does not include any aspect of user self-service, nor does it include a metering system and only has the rudimentary monitoring capability that has always been included in the solution.

This first approach seems to be most common in the industry. To complete the base cloud infrastructure, a company or service provider must purchase additional add-ons, which are often product-specific, and appear designed to lock you in to a single virtualization infrastructure.

The second approach is one that expands the architectural capabilities of the virtualization component and treats the cloud component of an IaaS solution as a higher level of capability and abstraction. This is the approach that Red Hat has taken with Red Hat Enterprise Virtualization (RHEV) 3.0 and its announced, upcoming, CloudForms solution.

Red Hat sees the base components of an IaaS cloud as key enablers at the virtualization layer. So RHEV 3.0 includes a power user portal (self-service & elasticity) giving users the ability to:

  • View assigned servers and desktops
  • Create/Edit/Delete VMs
  • Run VM with all options (including attach CD, etc)
  • Create/Edit/Delete/preview Snapshot
  • Create/Edit/Delete Templates
  • View VM statistics and status
  • View resource usage and statistics
    • Including network, storage, CPU and memory
  • Access the VM Console

RHEV 3.0 also includes an Enterprise Edition of Jasper Reports to provide advanced metering and reporting capability.

The only base component of a cloud architecture not included in RHEV 3.0 is the billing and charge-back capability, as it is not necessary in all solutions (optional). Generally, when billing and/or charge-back are required, they are implemented at a higher level, where they can include additional aspects and components of the cloud in the calculation of the resources consumed. This could include software licenses, physical disk usage, network usage, etc., that may or may not be consumed directly through the virtualized environment. Integrating the billing component into the virtualization layer would preclude a successful, extensible and inclusive billing and charge-back solution. For companies that require this capability, Red Hat has partners with solutions like Tivoli’s Usage and Accounting Manager (TUAM).

If Red Hat is offering an entire IaaS cloud solution, at no additional charge, as components of its RHEV 3.0 offering, then where does CloudForms come in?

Red Hat views cloud computing as more than just virtualizing your infrastructure. Clouds should provide abstraction from both the hardware and the virtualization themselves. A cloud infrastructure should give the enterprise or service provider the capability to use any sort of back end infrastructure they choose, physical or virtual, and provide automated, rules-based, dynamic access to those resources. That is the intent of Red Hat’s future CloudForms offering.

CloudForms employs a concept of Deployables which can define entire workloads, including database servers, app servers, web servers, all in a single package that can be deployed from a single end-user interface. Whereas RHEV 3.0 is going to deliver an entire IaaS cloud solution at one of the lowest costs in the industry, CloudForms will enable things like the automated deployment of en entire Platform as a Service (PaaS) solution with just a few clicks.

In general, virtualization will end where your virtualization solution provider decides it will. Most virtualization solutions provide only the basics, and call the rest (self-service, metering, reporting, etc.) “cloud” at significant additional cost. Red Hat’s virtualization solution provides everything an enterprise or service provider needs to stand up an IaaS offering at one low cost. Future offerings like CloudForms will serve to further enhance RHEV 3.0′s capabilities and ensure that customers have choice and flexibility in their cloud architectures, not just one solution that can’t fit all.

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