Limitations of This Version of ROMIO

• When used with any MPI implementation other than MPICH revision 1.2.1 or later, the status argument is not filled in any MPI-IO function. Consequently, MPI_Get_count and
  MPI_Get_elements will not work when passed the status object from an MPI-IO operation.

• Additionally, when used with any MPI implementation other than MPICH revision 1.2.1 or later, all MPI-IO functions return only two possible error codes--MPI_SUCCESS on success and MPI_ERR_UNKNOWN on failure.

• This version works only on a homogeneous cluster of machines, and only the ``native'' file data representation is supported.

• Shared file pointers are not supported on PVFS and IBM PIOFS file systems because they don't support fcntl file locks, and ROMIO uses that feature to implement shared file pointers.

• On HP machines running HPUX and on NEC SX-4, you need to compile Fortran programs with mpif90 instead of mpif77, because the f77 compilers on these machines don't support 8-byte integers.

• The file-open mode MPI_MODE_EXCL does not work on Intel PFS file system, due to a bug in PFS.