[ovs-dev] OVS and namespaces

Gary Kotton gkotton at redhat.com
Tue Oct 9 11:25:55 UTC 2012

On 10/08/2012 10:24 PM, Jesse Gross wrote:
> On Sat, Oct 6, 2012 at 10:21 AM, Gary Kotton<gkotton at redhat.com>  wrote:
>> Hi,
>> When Quantum is using OVS and namespaces there are problems when namespace
>> is being deleted. More specifically this is when a default gateway is
>> assigned to an interface that is used by the OVS. A simple way of
>> reproducing this is:
>> sudo ip netns exec<name>   ip route del ...
>> sudo ip netns exec<name>   ovs-vsctl del-port...
>>  From this moment on one is not able to access the namespace. The problem
>> does not occur when the traditional linux bridges are used.
>> Has anyone encountered this before?
> I haven't heard of it before and can't think of any reasons why it
> might be the case.  I tried reproducing it as well but couldn't
> although I'm not sure that I understand what you mean by not being
> able to access the namespace.
> Can you give a more detailed set of steps of how to reproduce this and
> more information about your environment (like the kernel version)?
Sorry for being a bit vague in the description. The problem occurs when 
running OVS with Quantum and namespaces are enabled (this is the 
default). It is very easy to reproduce. I have done this one Ubuntu 
12.04, Fedora 17 and Fedora 18. The easiest way of reproducing is to 
make use of devstack. (www.devstack.org)
Reproduction steps:
1.  git clone git://github.com/openstack-dev/devstack.git
2. Add the following to the file - stackrc
3. ./stack.sh
This launches openstack with OVS. The installtion will create 2 
namespaces. The first for the dhcp service and the second for the layer 
3 agent.
You can then run ' nova boot --image cirros-0.3.0-x86_64-uec --flavor 1 
t1' to launch a VM.
Once this is done you can try and delete the namespaces and you will see 
the problem.

Alternativey you can take a look at - 
https://fedoraproject.org/wiki/Test_Day:2012-09-18_OpenStack and the 
link https://fedoraproject.org/wiki/QA:Testcase_Quantum_V2


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