Resource and Virtualization Costs up in the Cloud: Models and Design Choices

Virtualization offers the potential for cost-effective service provisioning. For service providers who make significant investments in new virtualized data centers in support of private or public clouds, one of the serious challenges is the problem of recovering costs for new server hardware, software, network, storage, management, etc. Gaining visibility and accurately determining the cost of shared resources used by collocated services is essential for implementing a proper chargeback approach in cloud environments. We introduce and compare three different models for apportioning cost and champion the one that is least sensitive to workload placement decisions and provides the most robust and repeatable cost estimates. A detailed study involving 312 workloads from an HP customer environment demonstrates the result. Finally, we employ the cost model in a case study that evaluates the impact on the cost of exploiting different virtualization platform alternatives for the 312 workloads. For example, some workloads may cost more to host using certain virtualization platforms than on others or on standalone hosts. We demonstrate different decision points with potential cost savings of nearly 20% by "right-virtualizing" the workloads.