Because SharePoint encourages rapid growth and “viral” proliferation, user goals may conflict with the ability of the IT staff to deliver the desired services when needed within budgetary and manpower constraints. Flexibility is extremely valuable during this early period. If rapid growth and evolution can be supported at realistic costs, SharePoint can become an important tool to rapidly increase everyday productivity. vSphere facilitates this capability, allowing organizations to leverage the benefits of SharePoint on a pay-as-you-go basis. Because high availability features are inherent to the vSphere platform, these can be leveraged on demand. By virtualizing SharePoint, the common problems of deploying a complex, high-growth IT service are alleviated, allowing resources to be spent on maximizing the value of the tool in routine business practice.
Unlike some applications that have consistent workload patterns on a per user basis (for example, Exchange or SAP), SharePoint workloads can vary greatly depending on how the application is used within the organization. SharePoint services can be deployed in a wide variety of combinations to accommodate very specific application use cases. Even within a specific application use case, usage patterns can vary greatly depending on frequency of user access, time of day, document reads/writes, and document sizes.
Out of the box, vSphere offers several capabilities that enable you to quickly respond to changing usage patterns. Allocation of processor and memory resources to virtual machines can be easily changed to suit the most current business requirements and, in the case of Hot-Add, without any interruption to the operating system or application. You can use vMotion to migrate heavily used SharePoint virtual machines to another host to alleviate physical resource bottlenecks. Finally, template-based provisioning allows the rapid deployment of new SharePoint virtual machines to satisfy increased load.
Here is an updated support statement for running Sharepoint on vSphere.