Lxc 4.0 caused issue with starting container

Distro: Arch
LXD/LXC: 3.23/4.0
Kernel: 5.5.12-arch1-1

lxc start <container>

Output (formatted):

Error: Common start logic:
Failed to start device "eth0":
Failed to create the veth interfaces vethec99086b and veth9a2d5cde:
Failed to run: ip link add dev vethec99086b type veth peer name veth9a2d5cde:
Error: Unknown device type.

What happens if you run that command by hand?

ip link add dev vethec99086b type veth peer name veth9a2d5cde

I get: Error: Unknown device type.

Oh god. Apparently I updated my kernel too when I started updating lxc. Maybe this has something to do with it, not sure. After a system reboot, it works just fine now. Sorry about the fuss.

Yeah, sounds like you lost the veth.ko module that’s needed for this, causing this error.

This just happened to me too, for some reason veth.ko had vanished. Apt reinstalling linux-modules-blah put it back in place. When I reboot the server veth.ko has vanished again >.<

That’s very weird.

You may want to install debsums and run debsums -sa on your system.
This should highlight any file that’s missing or has been modified.