[Openstack-operators] Help adding my first compute-only node to my cloud controller with vlan networking

Samuel Winchenbach swinchen at gmail.com
Tue Aug 28 15:53:41 UTC 2012

Hi All,

I currently have an "all-in-one" cloud controller (cloudy) running and
am looking to add a compute-only node to it.  The cloud controller is
setup to use the VlanManager and has three networks:  A public network
(including a pool of floating IPs), a private network
for the instances, and a management network for various
services.  I followed the instructions here for adding multiple
compute nodes:
and at first it seemed like it worked correctly.  I launched a new vm
from the cloud controller, and verified that kvm was running on the
compute only node.   The problem was I could not access the VM at all
as the compute-only node did not seem to have a address.
I rebooted the compute-only node in hopes that that it would configure
the network correctly on boot, but unfortunately nova-compute failed
to start because of these errors:

from /var/log/nova/nova-compute.log:
2012-08-28 10:41:20 CRITICAL nova [-] Cannot get interface MTU on
'br1': No such device
2012-08-28 10:41:20 TRACE nova libvirtError: Cannot get interface MTU
on 'br1': No such device

and from /var/log/libvirt/libvirt.log:
2012-08-28 15:41:04.422+0000: 1309: error : virNetDevGetMTU:346 :
Cannot get interface MTU on 'br1': No such device
2012-08-28 15:41:04.566+0000: 1309: error : virNetDevGetIndex:656 :
Unable to get index for interface vnet0: No such device
2012-08-28 15:41:05.677+0000: 1303: error : virNetSocketReadWire:996 :
End of file while reading data: Input/output error

I don't see any errors in the logs on the cloud controller

Here are several questions for compute-only node:
1.  Is there any manual network configuration that must be done on
either node (creating br1, vnet0, etc) in order to correctly add the
compute-only node?
2.  Can/should the vlan and public interface be the same device?
3.  Sould the routing_source_ip be set to the address of the
compute-only node, or the cloud-controller ip's (management, private
or public)?
4. Seeing we are using vlan networking, do we need to setup up the
VLAN in the switch?

I have written up a document that describes our setup, including
nova-configuration.   I have not include glance/keystone configuration
as they seem to be working fine.  I stripped out all public ip/mac
addresses for security, and mangled the passwords... I am sure it
isn't that hard to read.

And advice, reference links, etc. would be greatly appreciated.

Thank you,

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