A x-based search is a fundamental functionality for storage systems. It allows users to nd desired datasets, where attributes of a dataset match an a x. While building inverted index to facilitate e cient a xbased keyword search is a common practice for standalone databases and for desktop le systems, building local indexes or adopting indexing techniques used in a standalone data store is insu cient for highperformance computing (HPC) systems due to the massive amount of data and distributed nature of the storage devices within a system. In this paper, we propose Distributed Adaptive Radix Tree (DART), to address the challenge of distributed a x-based keyword search on HPC systems. This trie-based approach is scalable in achieving ecient a x-based search and alleviating imbalanced keyword distribution and excessive requests on keywords at scale. Our evaluation at different scales shows that, comparing with the "full string hashing" use case of the most popular distributed indexing technique-Distributed Hash Table (DHT), DART achieves up to 55× better throughput with pre x search and with su x search, while achieving comparable throughput with exact and in x searches. Also, comparing to the "initial hashing" use case of DHT, DART maintains a balanced keyword distribution on distributed nodes and alleviates excessive query workload against popular keywords.