[Lustre-discuss] OSSes on dual IOH motherboards

[Mark Nelson]

Hi List,

I was wondering if anyone here has looked at the performance 
characteristics of lustre OSSes on dual tylersburg motherboards with 
raid controllers split up onto separate IO hubs.  I imagine that without 
proper pinning of service threads to the right CPUs/IOH and memory pools 
this could cause some nasty QPI contention.  Is this actually a problem 
in practice?  Is it possible to pin service threads in a reasonable way 
based on which OST is involved?  Anyone doing this on purpose to try and 
gain more overall PCIE bandwidth?

I imagine that in general it's probably best to stick with a single 
socket single IOH OSS.  No pinning to worry about, very direct QPI 
setup, consistent performance characteristics, etc.

Thanks,
Mark