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[Bram De Wilde <gbramdewilde@xxxxxxxxx>]

The bond was the culprit!

As we have been breaking our heads over this for close to 2 days it seems important enough to report here:

On our ubuntu 12.04 systems we had 2 bonded interfaces configured with an ip of 10.0.0.0/24 in an adaptive load balancing mode. We used this mode = 6 type bonding a bonding is not supported by the switch administrator. This appears not to be compatible with vlan tagged multi-host networking. @Vish: thanx for the suggestion, any idea where we would have to post this issue as a bug? I guess not openstack but rather the ifenslave people?
I would suspect this not to occur with other, switch based bonding modes but as we have no support for this I am unable to test...
This explained the inter vm communication to be really unreliable an drop out after a while. Using the eth0 interface instead of the bond0 as the vlan interface the network now is stable as ever.

Happy openstack users we will now be configuring our private cloud for stable operation in our department, thanx all!

We will be working on a solution for the name resolution in vlan tagged multi-host configurations, I will keep you posted as we progress.

Kind regards,

Bram

On 1-jun-2012, at 10:02, Vishvananda Ishaya wrote:

> 
> On Jun 1, 2012, at 12:46 AM, Bram De Wilde wrote:
> 
>> Thanx Vish,
>> 
>> On the name resolution: would you consider this a bug (I can file one if you would like) or a feature?
> 
> Bug if it is an easy fix :)
> 
>> Could this be fixed by changing the /usr/bin/nova-dhcpbridge script to load all mac, hostname, ip combinations for the database instead of just the physical hosts one? Or would this create other issues?
> 
> We would have to do some investigation into special settings. We want to make sure that the host doesn't respond to dhcp requests from other hosts. If it is possible to set up dnsmasq to do name resolution for the other hosts without handing ip addresses then we could do it this way. Someone will have to look into it.  It might have to be something a little more complicated like writing out a hosts file in addition to the dhcp file and telling dnsmasq to use it. If you want to investigate the easiest way to configure dnsmasq to do this, that would be a big help.
> 
> Vish
>