[Lxc-users] Dreadful network performance, only to host from container

[Matt Bailey]

Performance issues with networking and veth devices can be often
linked to the implementation of hardware acceleration in various
kernel drivers for various NICs.  I found this from a lot of toggling
of the acceleration tunables with ethtool. I'm sure there's a deeper
issue with the drivers, but it was just a trial and error discovery on
my part.

--
Matt Bailey
303.871.4923
Senior Software Specialist
University of Denver, UTS
http://du.edu
http://system42.net



On Fri, May 28, 2010 at 3:12 AM, Daniel Lezcano <daniel.lezcano at free.fr> wrote:
> On 05/28/2010 02:58 AM, Toby Corkindale wrote:
>>
>> On 28/05/10 05:55, Matt Bailey wrote:
>>>
>>> /usr/sbin/ethtool -K br0 sg off
>>> /usr/sbin/ethtool -K br0 tso off
>>>
>>> Might fix your problem, YMMV; this worked for me.
>>
>> Bam! Problem fixed.
>> All I needed was the 'sg' option - tso wasn't enabled anyway.
>>
>> Now getting a healthy 15-16 mbyte/sec.
>
> Great !
>
>> Thanks for that..
>>
>> Is this a bug in a driver somewhere that I should, or just something one
>> always needs to be aware of with LXC? (and thus should go in a FAQ)
>
> The true is the first time I see this problem solved by this trick. I
> suppose that has something related to the capabilities of your nic and the
> bridge inherit them. Dunno ...
>
> Matt,
>
> how did you find that ? Is it a problem spotted with the other
> virtualization solution (xen, vmware, qemu, openvz, ...) ? Do you have some
> pointer describing the problem/solution ? So we can add a FAQ with a good
> description / diagnostic of the problem.
>
> Thanks
>  -- Daniel
>
>