Parallel I/o as a pArallel Application

Metacomputing environments provide a software plat form for implementing parallel applications utilizing networked computing resources. Such programming environments offer a cost-effective alternative to paral lel machines for many classes of problems. Unfortu nately, most metacomputing environments either pro vide no I/O facilities, or serialize all I/O requests and thus limit application performance and scalability. PIOUS is a parallel file system designed to incorporate true parallel I/O into existing metacomputing environ ments. Because PIOUS is itself a parallel application, the functionality of a given metacomputing environ ment is extended without modification. This paper ex amines the PIOUS software architecture and program ming model and presents preliminary results from a prototype PIOUS implementation. Performance results are encouraging, demonstrating the potential of the PIOUS architecture for achieving scalable file system bandwidth in a network computing environment.