On Mon, 1 Nov 2010, Martin Pokorny wrote: ... > 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. ...
Is MPICH2 where ROMIO is developed these days? I found it pretty difficult to work out where the public face of its development was... On Tue, 2 Nov 2010, Larry wrote: > we use "localflock" in order to work with MPI-IO. "flock" may > consume more addtional resource than "localflock". ... Thanks for posting both of you, much appreciated :) Cripes, a tie (sort of). I think the following supports the "flock" option, but I would appreciate anyone putting-in a counter-opinion: 1) Is it a naive view that, if ROMIO asks for an flock, it needs it? And that if it doesn't on Lustre, then eventually ROMIO will be developed to stop asking for them? 2) A message in the list archive says that Cray recommend "flock" for their clusters, and it sounds like they use an enhanced version of ROMIO in their MPT product. The ADIO driver for Lustre certainly looks like it's still being actively worked-on to get it to maturity, and that various MPI implementations still need time to incorporate those changes. I note that the main MPI releases we use on our cluster (OpenMPI 1.4 and MVAPICH2 1.4 - we're a year behind) have V04 of ad_lustre, but MVAPICH2 is now closest to MPICH2 as it has since moved to V05. Looks like I need to do a software refresh... and recommend our MPI-IO users to use MVAPICH2 for the time being. Thanks, Mark -- ----------------------------------------------------------------- Mark Dixon Email : [email protected] HPC/Grid Systems Support Tel (int): 35429 Information Systems Services Tel (ext): +44(0)113 343 5429 University of Leeds, LS2 9JT, UK ----------------------------------------------------------------- _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
