System - Specific Implementations ADIO SIO low - level API PPFSGalleyHPSS PFS PIOFSUnix

In this paper, we propose a strategy for implementing parallel-I/O interfaces portably and eeciently. We have deened an abstract-device interface for parallel I/O, called ADIO. Any parallel-I/O API can be implemented on multiple le systems by implementing the API portably on top of ADIO, and implementing only ADIO on diierent le systems. This approach simpli-es the task of implementing an API and yet exploits the speciic high-performance features of individual le systems. We have used ADIO to implement the Intel PFS interface and subsets of MPI-IO and IBM PI-OFS interfaces on PFS, PIOFS, Unix, and NFS le systems. Our performance studies indicate that the overhead of using ADIO as an implementation strategy is very low.