The ROMIO Users Guide is in the file users-guide.ps.gz.
The book ``Using MPI-2: Advanced Features of the Message-Passing Interface,'' by William Gropp, Ewing Lusk, and Rajeev Thakur, MIT Press, 1999, provides a tutorial introduction to all aspects of MPI-2, including I/O. It has lots of example programs.
The following papers related to ROMIO are available online:
- Rajeev Thakur, William Gropp, and Ewing Lusk, ``Optimizing Noncontiguous Accesses in MPI-IO,'' Parallel Computing, (28)1:83--105, January 2002. http://www.mcs.anl.gov/~thakur/papers/mpi-io-noncontig.ps
- R. Thakur, W. Gropp, and E. Lusk, ``On Implementing MPI-IO Portably and with High Performance,'' in Proc. of the Sixth Workshop on I/O in Parallel and Distributed Systems, May 1999. http://www.mcs.anl.gov/~thakur/papers/mpio-impl.ps
- R. Thakur, W. Gropp, and E. Lusk, ``Data Sieving and Collective I/O in ROMIO,'' in Proc. of the 7th Symposium on the Frontiers of Massively Parallel Computation, February 1999, pp. 182--189. http://www.mcs.anl.gov/~thakur/papers/romio-coll.ps
- R. Thakur, W. Gropp, and E. Lusk, ``A Case for Using MPI's Derived Datatypes to Improve I/O Performance,'' in Proc. of SC98: High Performance Networking and Computing, November 1998. http://www.mcs.anl.gov/~thakur/dtype
- R. Thakur, W. Gropp, and E. Lusk, ``An Abstract-Device Interface for Implementing Portable Parallel-I/O Interfaces,'' in Proc. of the 6th Symposium on the Frontiers of Massively Parallel Computation, October 1996, pp. 180-187. http://www.mcs.anl.gov/~thakur/papers/adio.ps