Grid-Enabled Standards-based Data Management

The world´s largest scientific machine - the large hadron collider (LHC), situated outside Geneva, Switzerland - will generate some 15PB of data at rates up to 1.5 GB/s (in the case of the heavy-ion experiment, ALICE) to tape per year of operation. The processing of this data will be performed using a world-wide grid, the (worldwide) LHC computing grid built on top of the enabled grid for e-science and open science grid infrastructures. The LHC computing grid, which has offered a service for over two years now, is based upon a tier model comprising some 150 sites in tens of countries. In this paper, we describe the data management middleware stack - one of the key services provided by data grids. We give an overview of the different services implemented, a disk-based storage system which can support encryption, tools to manage the storage system and access files, the LCG file catalogue, and the file transfer service. We also review the relationship between these services.