A scalable approach to building large scale experimentation testbeds involves multiplexing the system resources for better utilization. Virtualization provides a convenient means of sharing testbed resources among experimenters. The degree of programmability and isolation achieved with such a setup is largely dependent on the type of technology used for virtualization. We consider OpenVZ and User Mode Linux (UML) for virtualization of the ORBIT wireless testbed and evaluate their relative merit. Our results show that OpenVZ, an operating system level virtualization mechanism significantly outperforms UML in terms of system overheads and performance isolation. We discuss both qualitative and quantitative performance features which could serve as guidelines for selection of a virtualization scheme for similar testbeds.
Gautam D. Bhanage, Ivan Seskar, Yanyong Zhang, Dip