Failed to create openStack instance

I had a similar problem, in my compute host i can see in the: journalctl -xfu neutron-linuxbridge-agent

Interface eth12 for physical network flat does not exist. Agent terminated!

My linuxbridge agent service was always restarting.

In this case, i was need to create the virtual devices veth file. My solution was:

1. vim /etc/systemd/network/25-veth-br-vlan-eth12.netdev

[NetDev]
Name=eth12
Kind=veth
[Peer]
Name=br-vlan-veth

2. And adding veth config in netplan file: vim /etc/netplan/00-installer-config.yaml

   ethernets:
       eno1:
         dhcp4: no
         mtu: 1500
       eno2:
         dhcp4: no
         mtu: 1500
       br-vlan-veth: {}
       eth12: {}

3. Apply netplan config:

netplan apply

4. Restart linuxbridge agent service:

systemctl restart neutron-linuxbridge-agent

PS: I needed to create the veth devices in all hosts using linuxbridge agent, like controller nodes and compute nodes.

If you are using OVS instead linuxbridge, this solution don't make sense to you, but can help someone that use linuxbridge.

Same here.. We managed to deploy OpenStack through Kolla-Ansible Unfortunately just cannot deploy an instance through Horizon. keep getting this error about the scheduler

Message Exceeded maximum number of retries. Exhausted all hosts available for >retrying build failures for instance 3539a5ba-b4f8-4dea-92a0-618e77d3ee93.

Code 500

Details Traceback (most recent call last): File

"/var/lib/kolla/venv/lib/python3.8/site-packages/nova/conductor/manager.py", line 665, in build_instances raise exception.MaxRetriesExceeded(reason=msg) nova.exception.MaxRetriesExceeded: Exceeded maximum number of retries. >Exhausted all hosts available for retrying build failures for instance >3539a5ba-b4f8-4dea-92a0-618e77d3ee93.

Created Oct. 3, 2021, 7:21 a.m.

But surprisingly the follwoing command seem to work

openstack server create \
--image cirros \
--flavor m1.tiny \
--key-name mykey \
--network demo-net \
demo1