HowTo: Copper 10 Gigabit NICs on Xen hypervisors

With the script below we were able to get a single VM to talk to another VM at slightly better than 3 gigabits per second. Evidently this is unheard of. Proprietary and vendor specific tweaks are not listed; but we may be tapped for assistance on this subject. Please contact us (or leave a comment) with any questions or concerns.

xen_10_gigabit.sh

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8 #!/bin/bash
ifconfig eth0 txqueuelen 300000
sysctl -w net.core.rmem_max=134217728 # BDP
sysctl -w net.core.wmem_max=134217728 # BDP
sysctl -w net.ipv4.tcp_rmem="4096 87380 134217728 " # _ _ BDP
sysctl -w net.ipv4.tcp_wmem="4096 65536 134217728 " # _ _ BDP
sysctl -w net.core.netdev_max_backlog=300000
ethtool -K eth0 gro on