[gmx-users] installation trouble with mpi support

[Justin MacCallum]

Hi Senthil,

> I had installed gromacs without mpi support on the master node of a cluster 
> (running linux redhat 7.1)
> Now I want to enable parallel runs and install it on the slave nodes also.
> so I first did a make distclean.
> 
> then ./configure --enable-mpi
> I get
> ...
> checking whether your compiler can handle assembly file (*.s )... no
> configure:error :Upgrade your compiler (or disable assembly loops)
> 
> and it stops
> 
> The version of the c compiler is 2.96. I would obviously not want to 
> disable assemble loops for performance reasons. I did not get this error 
> earlier when I had compiled Gromacs without mpi support. I am confused.
> 
> Are there other compile options that I can try to get around this?
> 
> Another question: Now, if I want to compile only mdrun with  mpi support, 
> how do  I do it?
> Is the following procedure correct?
> 
> ./configure --enable-mpi (Assuming I get it to work)
> make mdrun
> make install mdrun
> 
> How do  i get a separate mdrun with a different name or a suffix (say 
> mdrun-parallel), retaining my original non-mpi  mdrun

It might just be easier to use the rpm version. I'm assuming that you are
using mpich. The version of mpicc that comes with mpich does not seem to
be able to handle assembly files for some reason. You may want to install
lammpi (www.lam-mpi.org) as this is what most Gromacs users are using.
You can use the --program-suffix option of configure to append a suffix to
the name of your executables.

Justin