This work was supported in part by the Department of Energy ASCI program (Contract No. C70660017-3) and DOE 2000 program (Agreement No. DEFC 0398 ER 259 986). We would like to thank the Los Alamos National Laboratory for their sponsorship of TAU and DAQV projects. The authors sincerely acknowledge the important technical feedback provided by Steve Karmesin and Pete Beckman of LANL as well as the invaluable contributions of Ariya Lohavanichbutr, Chad Busche, and Michael Kaufman of the Department of Computer and Information Science, University of Oregon, on the implementation of the system.