Hi, When I use MPI_File_write_ordered to overwrite an existing file, the new file is not truncated to the appropriate size. For example, if I first create a new file and write "aa" from two nodes, the file contains "aaaa". Then I close the file, and compute for a while. Later, I reopen the file with amode=CREATE | WRONLY and write "b" from two nodes, the file contains "bbaa". I would have expected the file to contain only "bb".
Am I misunderstanding something, or is this a bug? Now that I think about it, this seems more like a problem with MPI_File_Open: this is the behavior I would have expected if I had reopened the file with amode=CREATE | RDRW. Shouldn't MPI_File_Open truncate the file to 0 when it is opened WRONLY and not APPEND? I'm able to obtain my desired result by calling MPI_File_get_position_shared() MPI_File_set_size() Thanks -Brian PS. I'm using (Open MPI) 1.1.2
