  We report on the production experience of the D0 experiment at the Fermilab
Tevatron, using the SAM data handling system with a variety of computing
hardware configurations, batch systems, and mass storage strategies. We have
stored more than 300 TB of data in the Fermilab Enstore mass storage system. We
deliver data through this system at an average rate of more than 2 TB/day to
analysis programs, with a substantial multiplication factor in the consumed
data through intelligent cache management. We handle more than 1.7 Million
files in this system and provide data delivery to user jobs at Fermilab on four
types of systems: a reconstruction farm, a large SMP system, a Linux batch
cluster, and a Linux desktop cluster. In addition, we import simulation data
generated at 6 sites worldwide, and deliver data to jobs at many more sites. We
describe the scope of the data handling deployment worldwide, the operational
experience with this system, and the feedback of that experience.
