Using virtual Lustre clients on the WAN for analysis of data from high energy physics experiments

We describe the work on creating system images of Lustre virtual clients in the ExTENCI project (Extending Science Through Enhanced National Cyberlnfrastructure), using several virtual technologies (Xen, VMware, VirtualBox, KVM). These virtual machines can be built at several levels, from a basic Linux installation (we use Scientific Linux 5 as an example), adding a Lustre client with Kerberos authentication, and up to complete clients including local or distributed (based on CernVM-FS) installations of the full CERN and project specific software stack for typical LHC experiments. The level, and size, of the images are determined by the users on demand. Various sites and individual users can just download and use them out of the box on Linux/UNIX, Windows and Mac OS X based hosts. We compare the performance of virtual clients with that of real physical systems for typical high energy physics applications like Monte Carlo simulations or analysis of data stored in ROOT trees.