When I try to use parallel I/O routines like MPI_File_write_at or MPI_File_read_at with the buffer argument being a derived datatype, I am unable to compile and just get an error of the nature:
MPI_FILE_READ_AT(fh, offset, buffer, count, datatype, status, ierr) 1 Error: There is no specific subroutine for the generic 'mpi_file_read_at' at (1) I'm using Open MPI 1.6 compiled with --with-mpi-f90-size=medium. I've also tried both gfortran and ifort, and both give the same compilation error. Has anyone else seen this behavior? Best regards, Paul