[R-sig-hpc] Rmpi and LAM: no spawning between 64 bit and 32 bit systems?

[Melwin]

Hi there,
thanks to the list, I got Rmpi and LAM running on a Suse 64 bit system.
Connecting LAM to slaves running Suse 32 bit (vm-linuxgeco1,  
vm-linuxgeco2) works fine as checked with lamexec on either machine:
> lamexec C hostname
	linuxmodel
	linuxmodel
	vm-linuxgeco1
	vm-linuxgeco1
	vm-linuxgeco2
	vm-linuxgeco2

However, spawning 32-bit slaves from from R on the 64 bit machine  
(linuxmodel) or vice versa gives an error:
	
mpi.spawn.Rslaves()

	Fehler in mpi.comm.spawn(slave = system.file("Rslaves.sh", package =  
"Rmpi"),  :
	  MPI_Error_string: error spawning process

while spawning from a 32 bit machine using only the other 32 bit slave  
works fine.

Is there a general requirement to have the same architecture and/or file  
layout in a Rmpi comm?

I suspect e.g. the parameter Rscript  
(=system.file("Rslaves.sh",package="Rmpi") by default) evaluates  
differently for the two architectures. Is there any need & way to specify  
this separately for each slave?

Thanks in advance,

Melwin

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