The High Performance Storage System (HPSS) is a new hierarchical storage software offering designed to handle the storage capacity and throughput requirements of the most demanding supercomputers and high-speed networks. 

This open, standards-based software product is scalable in terms of data capacity (petabytes), data transfer rates (gigabytes per second), number of files (billions), maximum file size (2^64 bytes), and geographic distribution of both software components and storage devices.

HPSS achieves these scalability features by supporting both direct-attached and network-attached disk and tape storage devices from multiple vendors, as well as by enabling distributed, parallel I/O through software striping.

HPSS has been, and continues to be, developed by a collaboration of US Government labs and IBM.