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
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
I'm able to obtain my desired result by calling
PS. I'm using (Open MPI) 1.1.2