International audienceDIRAC Project is developing software for building distributed computing systems for the needs of research communities. It provides a complete solution covering both Workload Management and Data Management tasks of accessing computing and storage resources. The Data Management subsystem of DIRAC includes all the necessary components to organize data in distributed storage systems. It has a versatile File Catalog (DFC) service to keep track of data file physical replicas. This service is a central component to build a logical File System of DIRAC presenting all the distributed storage elements as a single entity for the users with transparent access to the data. The DFC service provides also a Metadata Catalog functional...