SLES11 XEN Bridge bonding with bnx2x very slow

This document (7007658) is provided subject to the disclaimer at the end of this document.

Environment

OS: SLES11 SP1 XEN Host

Kernel: kernel-xen-2.6.32.27-0.2.2

Driverinfo:

filename: /lib/modules/2.6.32.27-0.2-xen/kernel/drivers/net/bnx2x.ko

firmware: bnx2x-e1h-5.2.13.0.fw

firmware: bnx2x-e1-5.2.13.0.fw

version: 1.52.1-7

license: GPL

description: Broadcom NetXtreme II BCM57710/57711/57711E Driver

Situation

Installing xen virtual guests on a SLES11 SP1 XEN Host with bnx2x driver in bonding configuration

Bonding device is configured as a XEN Bridge used for Installation of virtual machines.

When installing the virtual guests using this bridge the data is being transfered very slowly.

On the XEN Host (DOM0) you find the following error in /var/log /messages:

Jan 25 09:13:19 l5027022 kernel: [ 442.436200] bond0: received packets cannot be forwarded while LRO is enabled

Jan 25 09:13:19 l5027022 kernel: [ 442.536928] bond0: received packets cannot be forwarded while LRO is enabled

Resolution

It seems that the bond interface can not forward the incoming traffic to the XEN Bridge.

The solution is to switch off the tpx option of the interface

Stop networking

rcnetwork stop

vi /etc/modprobe.conf.local
add: options bnx2x disable_tpa=1

save

reload the bnx2x module:

modprobe -r bnx2x

lsmod | grep bnx2x -> should not deliver any answer

modprobe bnx2x

rcnetwork start

Additional Information

LRO (Large Receive Offload) is a technique to reduce CPU load in high bandwidth networks. (http://en.wikipedia.org/wiki/Large_receive_offload).

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.