On 8/29/2011 10:29 PM, Trey Dockendorf wrote:

Have you looked into using virt-manager? When I started using KVM I found that new VM provisioning was much simpler with that interface.

Alas, Virtmanager doesn't seem to be a supported program under Gentoo - the distribution I use. If its X-based, it wouldn't work anyhow - I'm strictly a command line shop.

Once you've created your domain with "virt-install" you can make changes using virsh.

virsh -c qemu:///system edit Test

That will allow you to directly edit the domain.

In the virt-install line you used "bridge=br0" , maybe replace that with "bridge=tap5". If that doesn't do it, once your editing the XML you can try something like the following...

I'm familiar with virsh edit and have used it to probe around a bit. Actually tried the "bridge=tap5" a few days ago and get the message:

ERROR internal error Failed to add tap interface to bridge. tap5 is not a bridge device

<interface type='bridge'>

<mac address='52:54:00:4d:74:c7'/>

<source bridge='tap5'/>

<model type='virtio'/>

<address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>

</interface>

That was created using virt-manager, so you probably need to use what virt-install created for your mac address and address.

Gave that a shot, attempting to create a new domain with "br0" replaced by "tap5" and got the same error message:

error: internal error Failed to add tap interface to bridge. tap5 is not a bridge device

Is your init failing on /dev/vda3 and then kernel panic? If so it's likely your guest OS doesn't have the necessary kernel modules loaded. Depending on your distro it will vary, but using CentOS 6 I've found they are automatically loaded. This is what's loaded in CentOS 6

Well, yes and no. Its failing with a kernel panic because KVM is being started with if=none instead of if=virtio. If I manually change it, it works fine. Just need to know where to update that in the domain XML file.

For what its worth, the image runs 100% fine with started manually with:

kvm -net nic,model=virtio -net tap,ifname=tap5,script=no -drive file=test1.img,if=virtio,boot=on -curses -no-reboot -m 2g -smp 2

So I know the image is good.

# lsmod | grep virtio

virtio_blk 5087 5

virtio_pci 6733 0

virtio_ring 7169 2 virtio_blk,virtio_pci

virtio 4824 2 virtio_blk,virtio_pci

Try changing the disk to ide , and then verifying your system is able to load the virtio modules.

Also , once you have your XML the way you like, if your going to stick with command line look at using virsh though I highly recommend virt-manager.

I'm still very new to KVM myself, so hopefully that was of some use

- Trey

Thanks!