  The increasingly collaborative, globalized nature of scientific research
combined with the need to share data and the explosion in data volumes present
an urgent need for a scientific data management system (SDMS). An SDMS presents
a logical and holistic view of data that greatly simplifies and empowers data
organization, curation, searching, sharing, dissemination, etc. We present
DataFed -- a lightweight, distributed SDMS that spans a federation of storage
systems within a loosely-coupled network of scientific facilities. Unlike
existing SDMS offerings, DataFed uses high-performance and scalable user
management and data transfer technologies that simplify deployment,
maintenance, and expansion of DataFed. DataFed provides web-based and
command-line interfaces to manage data and integrate with complex scientific
workflows. DataFed represents a step towards reproducible scientific research
by enabling reliable staging of the correct data at the desired environment.
