T. Harenberg (UNIVERSITY OF WUPPERTAL)
The D0 experiment at the Tevatron is collecting some 100 Terabytes of data each year and has a very high need of computing resources for the various parts of the physics program. D0 meets these demands by establishing a world - increasingly based on GRID technologies. Distributed resources are used for D0 MC production and data reprocessing of 1 billion events, requiring 250 TB to be transported over WANs. While in 2003 most of this computing at remote sites was distributed manually, some data reprocessing was performed with the EDG. In 2004 GRID tools are increasingly and successfully employed. We will report on performing MC production and data reprocessing using EDG and LCG. We will explain how the D0 computing environment was linked to these GRID platforms, and will discuss some lessons learned (for both Grid computing and preparing applications for distributed operation) from the D0 reprocessing on EDG, subjecting a generic Grid infrastructure to real data for the first time. An outlook on plans for applying LCG within D0 is given.