A quantitative comparison between xen and kvm
Andrea Chierici
Riccardo Veraldi
INFN-CNAF
{chierici,veraldi}@cnaf.infn.it
Abstract. Virtualization is a proven software technology that is rapidly transforming the IT
landscape and fundamentally changing the way that people compute. Recently all major
software producers (e.g. Microsoft and RedHat) developed or acquired virtualization
technologies. Our institute is a Tier1 for LHC experiments and is experiencing lots of benefits
from virtualization technologies, like improving fault tolerance, providing efficient hardware
resource usage and increasing security. Currently the virtualization solution adopted is xen,
which is well supported by the Scientific Linux distribution, widely adopted by the HEP
community. Since the HEP linux distribution is based on RedHat ES, we feel the need to
investigate performance and usability differences with the new kvm technology recently
acquired by RedHat. The case study of this work will be the LHCb experiment Tier2 site
hosted at our institute, where all major grid elements run on xen virtual machines smoothly.
We will investigate the impact on performance and stability that a migration to kvm would
entail on the Tier2 site, as well as the effort required by a system administrator to deploy the
migration. Several quantitative test results will be shown and explained in detail.