Server, storage, and network virtualization and the growing adoption of cloud computing has expanded both the complexity and the value of intelligent allocation and management of data center resources. Resource allocation in a cloud environment is of fundamental importance. There are many competing goals, with differing priorities, that contribute to optimizing virtual resource allocation and placement including performance, reliability, security, energy, etc. We have developed an open extensible architecture to provide placement recommendations which allows for different independently developed Domain Managers to provide input/advice on placement. We have further developed the means to orchestrate the placement, ensuring that the required configuration actions be enacted both before and after the migration of the virtual machine. This paper explores the topic of providing a core placement calculation and orchestration architecture to facilitate management of workload demands in a cloud environment. We describe this architecture for placement services and orchestration, and present some results from a prototype implementation. © 2011 IEEE.