The High Performance Storage System? (HPSS) is a mature hierarchical storage management (HSM) system that was developed around a network-centered architecture, with client access to storage provided through third-party controls. Because of this design, HPSS is able to leverage today's storage area network (SAN) infrastructures to provide cost-effective, large-scale storage systems and high performance global file access for clients. This paper gives an overview of the network centered architecture of HPSS and explains how the network centered approach allows HPSS to fully exploit SANs. (April 2002)