[Beowulf] NFS over IPoIB

Chris Samuel chris at csamuel.org
Fri Jun 12 22:49:35 PDT 2020

On Friday, 12 June 2020 2:36:26 PM PDT John McCulloch wrote:

> It is my understanding that setting MTU to 9000 is recommended but that
> seems to be applicable for 10GbE.

That depends how you're running your IB fabric.  In datagram mode (which I 
think is the default these days) you're limited to an MTU of 2044 bytes, but 
in connected mode (which used to be the default) you could get (from memory) a 

Back at VLSCI we ran with connected mode and 64KB MTUs with GPFS running on 
IPoIB (it was before you could run GPFS multi-homed on different IB fabrics 
with RDMA on both so we just ran it over TCP/IP instead).

All the best,
  Chris Samuel  :  http://www.csamuel.org/  :  Berkeley, CA, USA

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