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 64KB MTU. 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 -- Chris Samuel : http://www.csamuel.org/ : Berkeley, CA, USA _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit https://beowulf.org/cgi-bin/mailman/listinfo/beowulf
