Nowadays the operation of a modern university library is based on a reliable, high performance IT system. The University and National Library University of Debrecen has just finished making significant improvements to its IT infrastructure. It was a considerable advancement; it demanded serious changes in approach right from the planning: we accomplished a complete upgrade to a new serverpark. We aimed to establish a balanced server infrastructure, because we want to provide more efficient resource usage, quicker change to backup systems, and heightened user experience.

During the lecture, milestones and pitfalls of the period from exploring the requirements to operating the system will be reviewed. Components of the system and plans for future improvements will be presented. We will contrast what the new system offers as compared to the requirements, and how this system is capable of realizing these based on everyday experiences. A few practical things will be offered that can help building and operating similar systems.

Requirements collected during several years and answers provided relating to conceptual planning and implementation will be presented. We assigned serious role to a group of physically identical servers as well as to a shared storage connecting to the servers, whereon we planned a virtualization environment. After examining several technologies and vendor offers, we constructed our conception of a cluster based virtualization environment and conception of a SAN. After that, we decided to prepare Xen, Pacemaker bases with Debian Lenny Linux and with EMC storage. The new system makes it possible to start any virtual machine on any physical host, and to hot move them. Cluster members can take over each other's role based on well defined rules. In case of instability, faulty nodes can be fenced. Although we can buy out-of-the-box solutions for this purpose, our system's advantages consist of preferring open source components and easy migration to other virtualization platforms.