Comment 6 for bug 1910209

For the 16.04 case there was no dpdkvhostuserclient yet, so there it had to stay around anyway as OVS was the server.

But I agree that it is in issue in regard to "/var/run/openvswitch/vhostuser/vhu* is created by qemu once" that matches what I expect and indeed in that case clearing the var/run directory is bad indeed.

For the time being a temporary workaround could be to try using a different path.
I'm unsure if - without further tweaks - OVS and the Qemu rocessed are allowed to access it (apparmor is in place), but you could try putting the socket paths at e.g. /var/run/ovs-qemu-sockets/ and see if this works as an interim solution.