Overview of the MPIIO Parallel I/O Interface

Thanks to MPI, writing portable message passing parallel programs is almost a reality. One of the remaining problems is file I/O. Although parallel file systems support similar interfaces, the lack of a standard makes developing a truly portable program impossible. It is not feasible to develop large scientific applications from scratch for each generation of parallel machine, and, in the scientific world, a program is not considered truly portable unless it not only compiles, but also runs efficiently.

The MPI-IO interface is being proposed as an extension to the MPI standard to fill this need. MPI-IO supports a high-level interface to describe the partitioning of file data among processes, a collective interface describing complete transfers of global data structures between process memories and files, asynchronous I/O operations, allowing computation to be overlapped with I/O, and optimization of physical file layout on storage devices (disks).