[MPICH] A Question about MPI - Use the "-map" option in mpiexec

[Jayesh Krishna]

 Hi,
  If you would like to access use a remote machine's file system you will
have to share the file system using the "-map" option of the mpiexec command
in MPICH2 on windows (i.e., You cannot access the network shares from within
the MPI program if you do not use the "-map" option of mpiexec command). You
can find the details in the window's developer's guide available at
http://www-unix.mcs.anl.gov/mpi/mpich/ . Once you map the shared drive, to
say X:, you can access the file in the network share as
"X:\\folder1\\folder2\\filename" (without the quotes. Also make sure that
the string containing the filename has a '\0' at the end) from within your
MPI program.
  Let us know if you need any futher help in this regard.

Regards,
Jayesh

-----Original Message-----
From: owner-mpich-discuss at mcs.anl.gov
[mailto:owner-mpich-discuss at mcs.anl.gov] On Behalf Of Robert Latham
Sent: Thursday, September 20, 2007 12:34 PM
To: menglige
Cc: mpich-discuss
Subject: Re: [MPICH] A Question about MPI

On Thu, Sep 20, 2007 at 05:18:00PM +0800, menglige wrote:
> 
> int MPI_File_open(MPI_Comm comm, char * filename, int amode, MPI_Info 
> info, ??MPI_File * fh)
> 
> I want to open a file on the remote host.the host name is "node1" and file
name is "remotefile" in folder "E:\test" .
> How can i write the parameter "filename"?

Simce most MPI implementations are based on ROMIO, I'll tell you what ROMIO
can do about that, and it will likely work for you.

The NTFS driver for ROMIO doesn't go out and access remote machines.
Maybe Jayesh knows a trick or two, but you'll have to first export that
remote machine's file system to your client code (maybe a network shared
drive or shared folder.  

Once you've done that, specify the path like you would in windows Explorer.
I don't regularly use windows, so the following is
untested:

If you used a shared drive, something like char * filename = "y:\test" ;

or if you used a network folder then maybe char * filename =
\\remote_machine\test;

==rob

--
Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Lab, IL USA                 B29D F333 664A 4280 315B