[Lustre-discuss] MPI-IO / ROMIO support for Lustre

[Martin Pokorny]

Mark Dixon wrote:
> I'm trying to get the MPI-IO/ROMIO shipped with OpenMPI and MVAPICH2 
> working with our Lustre 1.8 filesystem. Looking back at the list archives, 
> 3 different solutions have been offered:
> 
> 1) Disable "data sieving"         (change default library behaviour)
> 2) Mount Lustre with "localflock" (flock consistent only within a node)
> 3) Mount Lustre with "flock"      (flock consistent across cluster)
> 
> However, it is not entirely clear which of these was considered the 
> "best". Could anyone who is using MPI-IO on Lustre comment which they 
> picked, please?

FWIW, we've been using MPICH2's MPI-IO/ROMIO/ADIO with Lustre (v 1.8) 
for several months now, and it's been working reliably. We do mount the 
Lustre filesystem with "flock"; at one time I thought it necessary, but 
I don't recall if I verified that after the initial problems with MPI-IO 
were resolved. Only a recent MPICH2 will have a working 
MPI-IO/ROMIO/ADIO for Lustre; perhaps the code would work with OpenMPI 
and MVAPICH2 as well.

-- 
Martin