[Beowulf] substantial RX packet drops during Pallas over e1000 (Rocks 4.1)

[Mark Hahn]

>     Running Rocks 4.1 on a 30 node system and seeing serious RX packet
> loss, drops and overruns while running heavy MPI i/o over e1000. I have

e1000, at least some chips, have interrupt-mitigation.
you should use ethtool to query these settings.
you might also tweak vm.min_free_kbytes.  how about 
the qlen as seen by ip/ifconfig?  also, have you tuned 
the *mem settings for the net stack itself like net.core.rmem_max?