On Monday 19 April 2010, Oliver Geisler wrote: > > Ah, that could do it. Open MPI's shared memory files are under /tmp. So > > if /tmp is NFS, you could get extremely high latencies because of dirty > > page writes out through NFS. > > > > You don't necessarily have to make /tmp disk-full -- if you just make > > OMPI's session directories go into a ramdisk instead of to NFS, that > > should also be sufficient. > > I just browsed FAQ and "ompi_info --param all all", but didn't find the > answer: > How do I set the OMPI session directory to point it to a ramdisk? > > And another question: > What would be a good size for the ram disk? One general value was > supposed by the FAQ with 128MB, but what is your experience? > (maybe a large topic by itself, so I have to try out, I guess)
I just wanted to add that space not used on a tmpfs (mount -t tmpfs ...) is not wasted. You can have an 8G tmpfs mounted but if you only use 100M that's how much RAM it uses. /Peter
signature.asc
Description: This is a digitally signed message part.
