There is a huge debate going on about private clouds and whether they are really clouds or just a buzzword for modern day on-premise data-centers. An article called Are Private Clouds Hogwash? does a great job of capturing the debate that has been raging on for over a year now.
Before I give my opinion, let’s look at the definition of a private cloud as put forth by NIST (National Institute of Standards and Technology):
Private cloud. The cloud infrastructure is operated solely for an organization. It may be managed by the organization or a third party and may exist on premise or off premise.
See entire cloud computing definition here
Based on this definition, one could argue that an on-premise private cloud is real and exists. I won’t argue that. What I will argue is this:
Does an on-premise private cloud make sense for any businesses other than vendors selling the hardware and software that allow private clouds to be built?
In my opinion, with a few exceptions, the answer is a resounding NO! (Yes, I just shouted). Before I get into my reasoning let me explain why I chose to use the word on-premise before the word private cloud. That was to differentiate between a private cloud contained within the walls of an enterprise, and a virtual private cloud, which is a private cloud provided by a third party. Virtual private clouds (VPC) make sense to me because you are still outsourcing your infrastructure needs to a third party and greatly reducing your capex. Of course, the term VPC has many different definitions too (that’s for another post some other day).
Now for my reasoning. One of the biggest benefits to the business for cloud computing is the reduction of capital expenditures brought about by outsourcing hardware and data center costs to a third party provider. Choosing to build your own cloud on-site is like building your own refrigerator. Sure you can do it and you can have total control over it, but it is way more expensive, labor intensive, and will take you forever to get it done. Wouldn’t it be simpler to just buy one with the latest and greatest technologies and energy efficiencies and just plug it in? Now I am not saying that going to the public cloud is as easy as plugging in, but it is a heck of lot easier than building your own.
Here are some exceptions where I think an on-premise private cloud might make sense.
Government: In my mind, it makes sense for a government to create it’s own private cloud to provide low cost computing and security to its many agencies and divisions. With organizations as big as governments with huge budgets and armies of resources, it may make sense to build a private on-premise cloud to service a variety of locations and greatly reduce the costs by eliminating the redundancy of each agency having its own primary and secondary data centers.
Large multi-located conglomerates: Extremely large organizations made up of numerous locations and numerous types of businesses can be served from an on-premise private cloud. Just like with government organizations, a huge organization can actually reduce the number of data centers if they were to build a private cloud in a centralized data center and scale up and down to meet the needs of entire organization and its user base.
These types of private clouds can be argued to be a community cloud (here is the NIST definition):
Community cloud. The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.
What about the rest of us?
If your organization does not fit into one of those two categories, I question why you think you need a private cloud. My belief is that most who think they do are simply afraid of giving up control of their hardware, data, and network. Now some people may argue that a hybrid model, public and private cloud combination, is the answer. The concept of a hybrid cloud makes perfect sense where you keep your data in the private cloud and push as much processing as possible to the public cloud to get the benefits of cheap processing cycles. However, is that really a private cloud or should we just be solving that with a service-oriented architecture, specifically a data services layer, where we leverage the cloud but access certain data elements on-premise?
Private clouds are a vendor’s dream. As Dave Linthicum has been saying, many vendors are simply “cloud washing” their products and creating hype to make buyers think they need to build their own clouds. Companies that buy this snake oil may consume their precious capital and human resources on long expensive projects just so they can declare that they have built their own cloud. There is nothing wrong with not putting certain data or applications in the public cloud and simply leverage good architecture and virtualization internally to modernize the data center. Just don’t call it a private cloud.