We are running an Oracle RAC database 2 node cluster on Cisco B200M4 / Firmware 3.2(3i)B / enic 126.96.36.199 / and see RX drops for one VNIC interface. We then have increased RX/TX queues, ring sizes and RSS in Ethernet Policy and will enable MTU 9000 tomorrow.
Still if I test with "iperf" and send packets with > 600 MBit/s over 10GbE interface, i see packet drops (ethtool -S eth1 -> rx_no_bufs).
Is this expected? Any idea on how to troubleshoot this further?
This generally indicates that the OS /Process in the OS isn't able to intake the packets fast enough. RSS, RX ring Size buffers, Interrupts, are the commonly adjusted tunables for your scenario, which it appears you have already adjusted.
Is the Baremetal OS, or a vitualized OS running RAC?
You running iperf with the -P and -w (-w 128M) switches?
[edit: use the -P to get parallel streams]