Deployment of grid gateways using virtual machines

Grid middleware is enabling resource sharing between computing centres across the world and sites with exist-ing clusters are eager to connect to the Grid. However, the hardware requirements for access to the Grid remain high: a standard Grid-Ireland gateway requires four sepa-rate servers. We propose the use of Virtual Machine (VM) technology to run multiple OS instances, allowing a full Grid gateway to be hosted on a single computer. This would significantly reduce the hardware, installation and management commit-ments required of a site that wants to connect to the Grid. In this paper, we outline the architecture of a single-box Grid gateway that we have developed for nationwide de-ployment. We evaluate implementations of this architec-ture on two popular open-source VM solutions: Xen and User-Mode Linux (UML). Our results show that Xen out-performs UML for installation tasks and standard gateway operations. Performance is close to that of standard Linux, and more than acceptable for everyday use. The Grid gateways support remote installation and man-agement to facilitate integration with a national Grid in-frastructure. Configuration is similar to that of sites run-ning multi-computer gateways, making it easy to keep site installation profiles synchronised. Our VM gateway architecture provides a low-cost entry path to the Grid and will be of interest to many institutions wishing to connect existing facilities to the Grid