[MPICH] Serial read-in of MPI-2 I/O

[Jean-Marc Saffroy]

On Tue, 18 Sep 2007, Peter Diamessis wrote:

> I've attached the actual F90 source code for the output. As you can see, 
> the four 3-D arrays containing the primitive variables are outputted, 
> followed by some secondary information on domain size & grid-spacing.

I think you forgot the attachment, or maybe it was removed by the mailing 
list robot.

> The "Using MPI-2" book says that files created by 'native' 
> representation are not portable. However, I'm assuming that Linux works 
> with Little Endian and thus this MPI-2 generated data can be read 
> serially on another Linux machine ?

Linux works with whatever endian is used by your processor. Some processor 
architectures can use only one of little endian (eg. x86, x64, Alpha) or 
big endian (SPARC, POWER); some can use both (IA64), and Linux uses only 
one endianness (Linux on IA64 is little endian).

Note that the format of your data can depend on the processor endianness, 
but also on the native word size (ie. 32 or 64 bits), and of course on 
your MPI implementation.

Maybe you should mention which MPI and processor you are using to produce 
and to read data, then maybe someone (not me) will be able to state if you 
can read it as 'native'; if not, the following page could tell you how 
your application should write its data so another app. can read it:

http://www.mhpcc.edu/training/workshop2/mpi_io/std/node198.html


-- 
saffroy at gmail.com