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How to disable TCP offloading on XenServer 6.2 host nic's

Started by Daniel Rosendahl , 15 December 2013 - 07:13 AM
7 replies to this topic

Daniel Rosendahl Members

Daniel Rosendahl
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Posted 15 December 2013 - 07:13 AM

I have used ethtool to disable TCP offloading on XenServer 6.2 host nic's.

The offload config on the host are by default:
Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: off
large-receive-offload: off
rx-vlan-offload: off
tx-vlan-offload: off
ntuple-filters: off
receive-hashing: off

I use the following command to set rx-checksumming, tx-checksumming, scatter-gather & generic-segmentation-offload to off:
# ethtool -K eth0 rx off tx off sg off tso off gso off

When I check the offload config again it looks correct. Everything is off.

After rebooting the offload config goes back to the default settings.

Does anyone know how to make the offload settings permanent?

 

 

 

 



Tobias Kreidl CTP Member

Tobias Kreidl
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Posted 15 December 2013 - 07:18 AM

You;would use an "xe pif-param-set" command, as shown for example in this script: http://virtualizationandstorage.wordpress.com/2011/06/21/xenserver-configuring-tcp-offload-script/

-=Tobias



Daniel Rosendahl Members

Daniel Rosendahl
  • 5 posts

Posted 15 December 2013 - 07:48 AM

As I understand this is an old blogg post. Will this work on 6.2?



konvikkt1 Members

kon vikkt
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Posted 15 December 2013 - 07:54 AM

yeah, Tobias is right.. -K switch will turn them off/onn on the fly.. to set it you would need to follow the article. Ofcourse that should work on 6.2 as this the basic linux setting of nic.



Tobias Kreidl CTP Member

Tobias Kreidl
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Posted 15 December 2013 - 07:59 AM

This is a generic Linux feature, so no reason to believe it's handled any differently on XenServers or VMs.  The ethtool utility should show your NIC supports the offloading features, as I'm sure you've already checked.  If you do some Web searching, you'll find material specific to XenServers, as well. Here's another article for reference: http://www.thesubodh.com/2012/05/toe-tcp-offload-engine-on-nic-packet.html



Darren Friedrich Members

Darren Friedrich
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Posted 17 January 2014 - 05:31 AM

Hi,

 

I used the script in the link provided by Tobias to disable the tcp offloading on my 6.2 farm. After restarting one of the hosts in the pool I receive the following error when I attempt to start a VM on it "an error occurred while attempting to configure an interface"

 

I have confirmed the VIF still exists and I can see the settings that were changed by the script.

 

Does anyone know how to rectify this?

 

Thanks!



Martin Kralicek Members

Martin Kralicek
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Posted 17 January 2014 - 08:38 AM

I can confirm that...I modified the script to sleep for 5 min and after that the issue is seem to be resolved, but sometimes it happens. So the emergency network reset is required. But I would like to know as well what is the reason.

 

Martin



intilop corp Members

intilop corp
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Posted 14 May 2014 - 07:11 AM

There are many types of TCP off load, the Full TCP offload, HBA and the chimney partial offload. There are lots of TCP manufacturer out there. To get the reliable one make sure that the company is legitimate and many years of experience in this kind of business.

 

I agree with Tobias Kreidl review.....