Enterprise virtualization management and private cloud management might seem to have much in common, but they actually have radical differences. Those differences are why it's best to build a private cloud from scratch rather than trying to morph an enterprise datacenter into a private cloud. When you understand the differences between these two management approaches, you can see how private clouds are the natural next step in the evolution of IT infrastructure management.
Consider so-called virtual machine (VM) sprawl. This rapid expansion of VMs commonly occurs when virtualization is first introduced into an organization. Enterprise virtualization seeks to limit VM sprawl. But the private cloud, which models itself on the public cloud encourages it. That's how hosting companies make money. Public cloud purveyors are paid for each VM that a user creates. Usefulness and efficiency aren’t considerations. IT might attach a few more controls to the process, but with appropriate internal chargeback mechanisms, a private cloud operator has no reason to put up barriers to VM sprawl. As long as cost accounting is instant, as it is with the public cloud, enterprise users will be as cautious with their private cloud development as are customers of public clouds.
Another difference is the basis for management. Enterprise virtualization is based on infrastructure: CPUs, memory, storage, and networks. The private cloud is based on services: applications, workflow, performance, and business continuity. The core of enterprise virtualization is the inventory of infrastructure components. IT techs typically build each application by hand out of these components. The core of the public cloud is service delivery. End users select an application from a catalog of standardized services, and then specify the performance and reliability they want. The private cloud infrastructure builds the requested service automatically.
Which brings us to a third difference: orchestration. In enterprise virtualization, the application build process is manually orchestrated by one or more IT staffers, possibly with the assistance of some tools. That manual orchestration requires time and expertise. Private cloud orchestration is automated from end-to-end, so no human intervention is necessary for a user to deploy a service from the enterprise catalog. The best implementations also give users direct access to instrumentation, so that they can monitor service performance and availability. Sure, you can slap a user portal on enterprise virtualization. You can script a service catalog to sort of automate delivery. You can create chargeback reports. But you'll never achieve the cohesion and reliability that purpose-built private cloud platforms deliver. Whether you design that platform yourself or buy it ready-built, starting with a clean sheet of paper is the only way to go. You can do that with a segment of enterprise virtualization resources, such as an existing server complex. But merging the two worlds is too expensive and has too few benefits.
The private cloud represents a major paradigm shift in the way that lines of business pay for IT services. But this shift enables IT innovation throughout an organization while relieving IT's huge project backlog. I believe that eventually the private cloud will supersede today's enterprise virtualization approach. Start designing your service catalog today, with input from your future cloud customer community. You'll then be well positioned to deploy the private cloud.