Selling the cloud, the private cloud computing, and the hybrid cloud seems to be the top goal of every major IT vendor these days -- and VMware is no exception. VMware was actually one of the leaders in the cloud space to show how virtualization can act as the foundation for cloud computing. Not surprisingly, since VMware has no global infrastructure services to sell, VMware places most of its emphasis on the private cloud and the hybrid cloud.

The concept of the public cloud is reasonably clear. A vendor provides a set of services that a customer can subscribe to. These services are typically Infrastructure as a Service (IaaS), Platform as a Service (PaaS), or Software as a Service (SaaS). IaaS typically means you're leasing VMs that are hosted on an Internet vendor's infrastructure. An example of IaaS is Amazon's Elastic Compute Cloud (EC2). PaaS typically means you lease operating services from a cloud vendor. Windows Azure is an example of this. With SaaS, you lease an application provided by a vendor. Microsoft Office 365 and Salesforce.com are examples of SaaS. Costs are typically metered by usage. Advantages of the cloud include lower capital expenditures and operating costs, as well as increased flexibility and scalability.

The private cloud is a newer concept and not quite as well understood. The main idea behind the private cloud is to take your existing infrastructure and make it more flexible, dynamic, and automated. Virtualization and technologies such as vMotion, Storage vMotion, and the Distributed Resource Scheduler (DRS) make this possible by automatically migrating workloads between pools of infrastructure. The primary advantage of the private cloud is that it moves your infrastructure away from being fixed, where one resource handles one workload, to a more fluid and dynamic infrastructure, where workloads can be automatically matched and moved to the resources that can best support them. The private cloud can also improve operational efficiency. In periods of low utilization, unused resources can be shut down. VMware's DRS performs both of these functions. The private cloud can also lay the groundwork for chargeback computing, in which IT consumers can be changed based on their resource utilization. VMware vCenter Chargeback performs this function.

VMware's principal cloud management product is vCloud Director. vCloud Director lets you provide and manage IaaS across multiple clusters in your data center. VCloud Director enables the creation of virtual data centers, as well as rapid provisioning of virtual machines (VMs) and virtual applications (vApps).