If a private cloud is nevertheless hosted on a public service, is it still a private cloud?

It may seem like a dumb question considering the very definition of a private cloud is that it is hosted on the enterprise's own internal architecture, so anything that is sourced outside is naturally a public cloud.

Yes, young Grasshopper, but you must realize that the cloud is currently in the market-hype phase -- and definitions in marketing, like truth in politics, are anything you can get the public to believe.

The thinking behind hosted private clouds goes like this: You still access resources and applications from the public cloud provider, but you do so on a dedicated infrastructure. In that way, you maintain your own network continuity, provide your own security, and basically use it as a remote extension of your own enterprise. Hence, the public private cloud.

We're seeing more and more of these setups now that enterprises are becoming increasingly vocal about their privacy and security concerns surrounding public cloud offerings. A Massachusetts cloud provider called InetServices recently expanded its portfolio with the Virtual Private Data Center. The benefits include all of the provisioning and scalability of its public cloud system, with the added security of knowing that no one else is using that infrastructure. The company provides either VMware ESX or Microsoft Hyper-V virtualization, as well as heterogeneous support for Windows and Linux.

Such services are taking a cue from Rackspace, which introduced the Rackspace Private Cloud service last summer. The service utilizes the company's dedicated virtual server (DVS) platform capable of providing up to 35 GHz processing with 32 GB of RAM and tied to upwards of 500 GB Fibre Channel or SATA SANs over 1 TB networking.

Naturally, these kinds of services lend themselves to hybrid cloud infrastructures, in which data is transported between public and private clouds according to their resource requirements. In theory, these transfers are seamless, so users need not concern themselves with where their data is going, but the reality is that these types of architectures are a lot more difficult to maintain than boosters would have you believe.

Which brings us to the latest intermingling of public and private clouds -- the public architecture that actually is hosted on internal infrastructure. This is the approach Unisys is taking with its Secure Private Cloud Solution. The idea is to essentially recreate Unisys' public cloud environment on your existing hardware using a pre-loaded, easily deployable software stack that provides all the virtualization, network optimization and data management tools you need to get up and running. And once the private system is in place, it can be easily integrated with Unisys' public offering. As for security, Mike Vizard at our CTO Edge site points out that the system includes the same technology that Unisys developed for the National Security Agency (NSA).

The ultimate goal in all of this is to help enterprises overcome the fear, warranted or not, that cloud services are not to be trusted with mission-critical data. By providing mixed public-private services, the hope is that the lines will soon be blurred enough that enterprises will see that data is no more or less safe on your own hardware than on someone else's.

And while that is probably true, it's a shame cloud providers simply can't make that fact plain through robust technology demonstrations rather than back-handed service compilations.