Clustered data storage for multi-site fusion experiments

The LABCOM data acquisition and management system already provides full functionality to both local and remote participants in Large Helical Device (LHD) experiments. This study newly added a function for dealing with raw experimental data not only from one experimental device but also from multiple distant sites. Its original distributed structure has enabled the multi-site modification to be made with a minimum of change, mainly within the data location indexing database for clustered storage. However, access permissions and restrictions for each site's data and users should be strictly implemented. The system began operation in 2008 under bilateral collaborations between the LHD, QUEST, and GAMMA10 experiments, with the goal of organizing a Fusion Virtual Laboratory in Japan.