@InProceedings{ching:noncontiguous, author = {Avery Ching and Alok Choudhary and Kenin Coloma and Wei-keng Liao and Robert Ross and William Gropp}, title = {Noncontiguous {I/O} Accesses Through {MPI-IO}}, booktitle = {Proceedings of the Third IEEE/ACM International Symposium on Cluster Computing and the Grid}, year = {2003}, month = {May}, pages = {104--111}, publisher = {IEEE Computer Society Press}, address = {Tokyo, Japan}, URL = {http://csdl.computer.org/comp/proceedings/ccgrid/2003/1919/00/19190104abs.htm}, keywords = {parallel I/O, MPI-IO, ROMIO, list I/O, noncontiguous access, pario-bib}, abstract = {I/O performance remains a weakness of parallel computing systems today. While this weakness is partly attributed to rapid advances in other system components, I/O interfaces available to programmers and the I/O methods supported by file systems have traditionally not matched efficiently with the types of I/O operations that scientific applications perform, particularly noncontiguous accesses. The MPI-IO interface allows for rich descriptions of the I/O patterns desired for scientific applications and implementations such as ROMIO have taken advantage of this ability while remaining limited by underlying file system methods. \par A method of noncontiguous data access, list I/O, was recently implemented in the Parallel Virtual File System (PVFS). We implement support for this interface in the ROMIO MPI-IO implementation. Through a suite of non-contiguous I/O tests we compared ROMIO list I/O to current methods of ROMIO noncontiguous access and found that the list I/O interface provides performance benefits in many noncontiguous cases.} }