[ovs-discuss] management of tap devices

westlake westlake2012 at videotron.ca
Sat Oct 11 19:17:20 UTC 2014


Not sure why this happens, and I think I got a thing or two wrong.. but 
over here testing on debian it's not only confusing it is also broken.. 
hopefully this has all been fixed.


On 11/10/14 12:10 PM, westlake wrote:
> I noticed when using ovs-vsctl to create tuntap devices, ovs-vsctl is
> also able to destroy the same tuntap device outside ovs.
>
> eg,
> ovs-vsctl add-port <bridge name> <tap dev> -- set Interface <tap dev>
> type=tap
>
> ifconfig -a , lists the tuntap device
>
> This device can be taken out of the ifconfig -a list using "ovs-vsctl
> del-port ..."
>
> However creating the tuntap device with "ip tuntap", later adding it
> with "ovs-vsctl add-port" then trying to destroy it with "ovs-vsctl
> del-port .." does not destroy the device but only deletes it from its
> database.
>
> The question I have is if there's a "management"/auto-creation tag I can
> set on tap devices so that the ovs daemon will auto-create them on startup.
>
> If I can add to this, I'm actually working towards a larger problem...
>
> The "index" networking ID number for "ip tuntap" generated tap devices
> on consecutive reboots will not match the ones stored in the ovs database.
>
> For now I'm avoiding, debian's ifupdown interfaces file, as the problem
> is even worse.. Here I'm using edition 2.3, and the command
>
> "ovs-vsctl add-port <bridge name> <tap dev> -- set Interface <tap dev>
> type=tap "
>
> ^ Only creates the device properly halfway. The tap device shows up
> properly with ifconfig -a, but a kvm instance complains about
> /dev/net/tun for the same tap device.
>
> Anyone here knows these problems have been addressed with edition 2.4?
>
> I can find workarounds with scripting around with with rc.local to get
> things working, but I'm looking for a better solution.
>
> thanks




More information about the discuss mailing list