This week, I want to take the contrary position -- why private clouds are not the future of cloud computing, and, in fact, will prove too daunting for IT organizations.

First, one of the main reasons posited for private clouds is that they enable IT organizations to repurpose existing infrastructure. But is that really true? The key to automating the bottom half of the chart -- the infrastructure portion -- is to use equipment that can be configured remotely with automated measures. In other words, the equipment must be capable of exposing an API that an automated configuration system can interact with. This kind of functionality is the hallmark of up-to-date equipment. Unfortunately, most data centers are full of equipment that does not have this functionality; instead they have a mishmosh of equipment of various vintages, much of which requires manual configuration. In other words, automating much of the existing infrastructure is a non-starter.

Worse, even if the data center equipment is mostly of recent vintage, additional investment will be necessary. Add-on equipment to manage networking and storage will be required for cloud capability. Absent sufficient investment to ensure every part of the kit is automation-ready, the goal of end-to-end automation that is cloud computing will fall short. That is to say, more capital investment is going to be required to get to the Nirvana of a private cloud. And in these economic times, where IT is slashing budgets, an initiative that calls for more investment is not really practicable.

Second, what most vendors aren't saying right now is that, even if you're ready and capable of supporting incremental capital investment, a private cloud is not an easy-to-assemble arrangement like something from Ikea. Far from it. In order to make all the pieces ready to work together and be provisioned in a holistic fashion, a great deal of manual work is required. Each of the vendors offers a range of professional services designed to help IT organizations get their cloud up and running. Left unsaid is the fact that creating a private cloud requires great slathers of expensive consulting. So on top of the additional hardware costs, there will be additional fees for the vendor's personnel to "help you take advantage of your existing infrastructure."

All in all, the ambition to leverage existing infrastructure to create a low cost private cloud may be a chimera -- a misguided vision of achieving vast improvement with little additional investment. Far more likely is vastly lowered marginal costs achieved by the investment of large amounts of capital and consulting.