The Grid Laboratory of Wisconsin (GLOW), a partnership between several research departments at the University of Wisconsin, have installed almost 200TB, or 200,000GB, of Xserve RAID arrays. As a comparison, 200TB of storage is enough to hold 2.75 years of high definition video, 25,000 full length DVD movies, 323,000 CDs, 20 printed collections of the Library of Congress, or over 1000 Wikipedias.
The GLOW storage installation is physically split between the departments of Computer Sciences and High Energy Physics. Each Xserve RAID is attached to a dedicated Linux node running Fedora Core via an Apple Fibre Channel PCI-X Card and is either directly accessed via various mechanisms, such as over the network via gigabit ethernet, or aggregated using tools such as dCache.
Aside from the GLOW initiative, the university also has Xserve RAID storage systems in use in other areas as well.
GLOW storage installation at Computer Sciences
GLOW storage installation at High Energy Physics