[Lxc-users] Fwd: RE: Price Request For lxc.org

[Derek Simkowiak]

 > /Add it to the possible wish list along with the MAC address prefix/

     If there is interest in an official LXC vendor MAC address prefix, 
I'd like to call your attention to this Linux kernel bug:

https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/584048
https://www.redhat.com/archives/libvir-list/2010-July/msg00450.html

     These bug reports are for KVM with bridging, however, I have seen 
the same symptom using LXC.  The symptom is that the network bridge goes 
dead for several seconds when starting or stopping containers.  The root 
of the issue is in the Linux kernel, and how it handles the MAC address 
of bridges (and bond interfaces, too).

     In summary, the MAC prefix can't be arbitrary, because a low MAC 
vendor prefix causes a short-term network blackout on the bridge device 
when starting or stopping LXC containers, or KVM/qemu VMs, or any other 
environment using non-physical interfaces.  The blackout is (apparently) 
caused by the bridge changing its MAC address.

     I have added a workaround to my script for this bug (see Comment 
#60 in Launchpad, above).  According to Serge Hallyn: "That it is a 
general bridge property is indeed known. The fix in this bug is, like 
your script, simply working around that fact."


Thank You,
Derek Simkowiak
derek at simkowiak.net

On 10/11/2011 06:08 AM, Brian K. White wrote:
> That's a pretty substantial reduction. Add it to the possible wish list
> along with the MAC address prefix. Sadly I never finished the research
> to get that. The $600 is easy, the time to figure out what you're
> supposed to do is not ;)
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linuxcontainers.org/pipermail/lxc-users/attachments/20111011/2ba9eb79/attachment.html>