I'm using an Intel® Ethernet Server Adapter X520-SR1 device in Ubuntu 12.04, kernel 3.16..0-52, to receive 10GbE packets. The ixgbe driver module is version 3.19.1-k.
When I run the command ethtool -g eth6 I see the following:
Ring parameters for eth6:
Pre-set maximums:
RX : 4096
RX Mini: 0
RX Jumbo: 0
TX: 4096
Current hardware settings:
RX: 4096
RX Mini: 0
RX Jumbo: 0
TX: 512
I bumped up RX descriptors from 512 to 4096 to try and reduce packet loss.
However, I'm a bit confused why "RX Jumbo" says the pre-set max is 0. I'm currently sending packets that are about ~4kB, so fall into the jumbo packet realm. I increased MTU from 1500 to 9000 with ifconfig eth6 mtu 9000. It's working fine (but some drops here and there). The docs seem to indicate jumbo frames up to 9k are supported by the x520 series.
Should I worry about ethtool reporting 0 Rx Jumbo descriptors? If so, do I just need a new ixgbe driver or ethtool update?