The question was how you'd configure a concrete MPI implementation to separate MPI-IO traffic from the rest if it was a good idea. We have the Infiniband (or s

The question was how you'd configure a concrete MPI implementation to separate MPI-IO traffic from the rest if it was a good idea. We have the Infiniband (or similar) fabric, and we understand it -- in my case better than the Ethernet one we're proposed to have to understand as well, and we're typically not "network engineers" doing this stuff. I disagree that Infiniband is more challenging anyway, having had and known about bad problems with cluster Ethernet. Then this 10G Ethernet get a whole 10% extra bandwidth on top of current HPC fabrics while presumably adding jitter. HPC codes don't generally spend 60% checkpointing, and "data warehouse applications" typically aren't of interest to us, but we can do mapreduce-type things fast. See the bits about redundancy and the advantage of RDMA in the checkpointing filesystem.