On Tue, Apr 3, 2012 at 11:23 AM, Jon <three1...@gmail.com> wrote:
> Hello All,
>
> I am attempting to use OpenV Switch as a replacement for the standard
> bridge controls for KVM.
>
> After a reboot, I am receiving the following error when attempting to
> start my KVM VMs:
>
> root@kitt:~# virsh start solo.rebase.ubuntu-server-11.10-oneiric-x86_64
> error: Failed to start domain
> solo.rebase.ubuntu-server-11.10-oneiric-x86_64
> error: Unable to add bridge br0 port vnet0: Invalid argument
>
> I had this problem yesterday, and resolved it by creating the bridge by
> running the following commands,
>
> ovs-vsctl add-br br0
> ovs-vsctl add-port br0 eth1
>
> When running these commands today, I receive the following errors:
>
> root@kitt:~# ovs-vsctl add-br br0
> ovs-vsctl: cannot create a bridge named br0 because a bridge named br0
> already exists
> root@kitt:~# ovs-vsctl add-port br0 eth1
> ovs-vsctl: cannot create a port named eth1 because a port named eth1
> already exists on bridge br0
>
> Yesterday, when I ran the ovs-vsctl commands, I was able to successfully
> start my VMs, I had a power outage, and the machine was rebooted, today I
> am unable to "add the bridge" again, because it already exists, but I am
> unable to use the bridge.
>
> I am running Ubuntu 12.04 Server, but am pretty sure this isn't the
> problem as it was working.
>
> I followed the instructions found here for installing and configuring
> OpenV Switch:
> http://blog.allanglesit.com/2012/03/linux-kvm-ubuntu-12-04-with-openvswitch/
> Initially, I only was using one NIC, so when I attempted to add the
> bridge, I killed my network connection; of course this is a remote
> machine... :)
>
> Anyway, after rebooting, I still had no network, so I destroyed the bridge
> and recreated it using my 2nd NIC Eth1 (Eth2 is management, Eth1 is my
> bridge interface; my 2nd NIC is Eth1... it's just the way they are placed
> on the chassis), then I was able to successfully start my VM with the
> command:
>
> root@kitt:~# virsh start solo.rebase.ubuntu-server-11.10-oneiric-x86_64
>
> Today, after my reboot, it returns an error:
> error: Failed to start domain
> solo.rebase.ubuntu-server-11.10-oneiric-x86_64
> error: Unable to add bridge br0 port vnet0: Invalid argument
>
> On a hunch, I recreated my steps from yesterday:
>
> root@kitt:~# ovs-vsctl del-br br0
> root@kitt:~# ovs-vsctl add-br br0
> root@kitt:~# ovs-vsctl add-port br0 eth1
> root@kitt:~# virsh start solo.rebase.ubuntu-server-11.10-oneiric-x86_64
> Domain solo.rebase.ubuntu-server-11.10-oneiric-x86_64 started
>
> And success... This is great for now, as my VMs are up and running (and
> fortunately this is not a production environment, so I don't have customers
> yelling at me), but what happens next time I want to reboot my VM Host
> (admittedly it doesn't happen often, but as Ubuntu is still in beta,
> updates are more frequent), I really don't want to have to go through this
> song and dance every time I reboot...
>
> Initially, I thought it might have something to do with the qemu-ifup
> script, because it uses brctl,
>
> I could be wrong, but I believe the problem is that Open vSwitch keeps its
state
after abrupt reboots, while libvirt discards it. Hence the vnet0 interface
remains
hanging to the bridge from the old session and libvirt can't add it with
duplicate
name after the reboot.
To verify this: Next time you can't start the VM, could you make sure that
vnet0 interface is already attached to the bridge even when VM is not
running?
#!/bin/sh
>
> nic=$1
>
> if [ -f /etc/default/qemu-kvm ]; then
> . /etc/default/qemu-kvm
> fi
>
> if [ -z "$TAPBR" ]; then
> switch=$(ip route list | awk '/^default / { print $5 }')
> if [ ! -d "/sys/class/net/${switch}/bridge" ]; then
> switch=virbr0
> fi
> else
> switch=$TAPBR
> fi
>
> ifconfig $nic 0.0.0.0 up
> brctl addif ${switch} $nic
>
> But after deleting and recreating the bridge, I am not so sure... I would
> think that if the /etc/qemu-ifup script was executed, then it wouldn't
> matter if I made changes to openvswitch. Admittedly, I don't know enough
> about libvert and the way it manages networks to be certain if it is even a
> openvswitch problem, can anyone shed some light on the problem?
>
> Thanks for your time,
> Jon
>
> _______________________________________________
> discuss mailing list
> discuss@openvswitch.org
> http://openvswitch.org/mailman/listinfo/discuss
>
>
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