  We describe our work in implementing a wide-area distributed file system for
the NSF TeraGrid. The system, called XUFS, allows private distributed name
spaces to be created for transparent access to personal files across over 9000
computer nodes. XUFS builds on many principles from prior distributed file
systems research, but extends key design goals to support the workflow of
computational science researchers. Specifically, XUFS supports file access from
the desktop to the wide-area network seamlessly, survives transient
disconnected operations robustly, and demonstrates comparable or better
throughput than some current high performance file systems on the wide-area
network.
