The core problem: I need direct NFS access from a VM to the same server used for OpenNebula datastores. Same server, different shares. The host has a single ‘team’ interface with vlan children, and all of our existing vnets use the 802.1Q VN_MAD. This does not work if the host has an existing vlan child, reporting this in the VM log:
Fri Feb 24 20:16:37 2023 [Z0][VMM][I]: pre: Executed “sudo brctl addbr b-v800”.
Fri Feb 24 20:16:37 2023 [Z0][VMM][I]: pre: Executed “sudo ip link set b-v800 up”.
Fri Feb 24 20:16:37 2023 [Z0][VMM][E]: pre: Command “sudo ip link add link team0 name team0.800 mtu 9000 type vlan id 800” failed.
Fri Feb 24 20:16:37 2023 [Z0][VMM][E]: pre: RTNETLINK answers: File exists
Fri Feb 24 20:16:37 2023 [Z0][VMM][E]: RTNETLINK answers: File exists
Fri Feb 24 20:16:37 2023 [Z0][VMM][E]:
Fri Feb 24 20:16:37 2023 [Z0][VMM][I]: ExitCode: 2
Fri Feb 24 20:16:37 2023 [Z0][VMM][I]: Failed to execute network driver operation: pre.
Fri Feb 24 20:16:37 2023 [Z0][VMM][E]: Error attaching new VM NIC: 802.1Q: RTNETLINK answers: File exists
I have tried using “bridged” mode, but that only adds the new guest interface to a bridge all by itself.
What I need is something that acts like just another IP on the same subnet as the existing vlan interface with an existing address used by the host. I have not found a way, although it seems like it should be simple.