Measuring performances of linux hyper visors

Virtualisation is a now proven software technology that is rapidly transforming the I T landscape and fundamentally changing the way people make computations and implement services. Recently, all major software producers (e.g., Microsoft and Red Hat) developed or acquired virtualisation technologies. Our institute (http://www.CNAF.INFN.it) is a Tier l for experiments carried on at the Large Hadron Collider at CERN (http://lhc.web.CERN.ch/lhc/) and is experiencing several benefits from virtualisation technologies, like improving fault tolerance, providing efficient hardware resource usage and increasing security. Currently, the virtualisation solution we adopted is xen, which is well supported by the Scientific Linux distribution, widely used by the High-Energy Physics (HEP) community. Since Scientific Linux is based on Red Hat E S, we felt the need to investigate performances and usability differences with the new k vm technology, recently acquired by Red Hat. The case study of this work is the Tier2 site for the LHCb experiment hosted at our institute; all major grid elements for this Tier2 run on xen virtual machines smoothly. We will investigate the impact on performance and stability that a migration to k vm would entail on the Tier2 site, as well as the effort required by a system administrator to deploy the migration.