[libvirt] Koan, KVM and PXE

[Fabien Dupont <evenit gmail com>]

Hi all.

I use Cobbler to manage my PXE boot. I would like to extend my use to manage VM deployment with Koan. But I have a problem related to network and my VM can't boot. I have already posted on Cobbler mailing-list but it's probably on kvm/libvirt side...

I
am on Fedora 10 with Cobbler 1.6.4 and Koan 1.6.3 (latest available
from stable repos), and libvirt 0.5.1-2.fc10. I would like to create VMs using KVM thus I have
imported FC10 DVD, added Everything and Updates repos and created a
host using the profile created during import. The system has the
following properties :

root# cobbler system report vmtest
system                : vmtest

profile               : fedora-core-10-x86_64
comment               : 

created               : Fri May  8 13:43:40 2009
gateway               : 192.168.1.254

hostname              : vmtest
image                 : 

kernel options        : {}
kernel options post   : {}

kickstart             : <<inherit>>
ks metadata           : {}

mgmt classes          : []
modified              : Sat May 23 18:42:59 2009

name servers          : []
name servers search   : []

netboot enabled?      : True
owners                : ['admin']

redhat mgmt key       : <<inherit>>
redhat mgmt server    : <<inherit>>

server                : <<inherit>>
template files        : {}

virt cpus             : <<inherit>>
virt file size        : <<inherit>>

virt path             : <<inherit>>
virt ram              : <<inherit>>

virt type             : <<inherit>>
power type            : ipmitool

power address         : 
power user            : 

power password        : 
power id              : 

interface        : eth0
  mac address    : ff:00:00:01:00:00

  bonding        : 
  bonding_master : 

  bonding_opts   : 
  is static?     : True

  ip address     : 192.168.1.201
  subnet         : 255.255.255.0

  static routes  : []
  dns name       : vmtest.local

  dhcp tag       : 
  virt bridge    : br0

As
you can see, I use a bridged network with a real bridge create with the
method described on the wiki (eth0 is the real interface and br0 the
bridge).
Then I create the VM using : koan --server=cobbler.evenit.info --virt --system=vmtest
The
VM is correctly created and started : kernel and initrd are correctly
set, virtual hard drive is right and network interface seems right.

root# ps -edf | grep kvm
root     19484 23655 67 21:54 ?       
00:00:06 /usr/bin/qemu-kvm -S -M pc -m 256 -smp 1 -name vmtest -monitor
pty -no-reboot -boot c -kernel /var/lib/libvirt/boot/

virtinst-vmlinuz.omv9yr -initrd /var/lib/libvirt/boot/virtinst-initrd.img.Ufj-qc -append ks=http://cobbler.evenit.info/cblr/svc/op/ks/system/vmtest ksdevice=link kssendmac lang= text  method=http://cobbler.evenit.info:80/cblr/links/fedora-core-10-x86_64/ -drive file=/var/lib/libvirt/images/vmtest-disk0,if=virtio,index=0,boot=on -net nic,macaddr=ff:00:00:01:00:00,vlan=0,model=virtio -net tap,fd=14,script=,vlan=0,ifname=vnet0 -serial pty -parallel none -usb -vnc 127.0.0.1:0 -k en-us

But, when I open the VM display with virt-manager, I see that installation can't start as DHCP is not answering... There's no trace of the DHCP requests on DHCP server and vnet0 seems to have no trafic :

[root lilith ~]# netstat -i
Table d'interfaces noyau
Iface       MTU Met    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
br0        1500   0   173524      0      0      0   261005      0      0      0 BMRU
eth0       1500   0   173589      0      0      0   260909      0      0      0 BMPRU
lo        16436   0    29105      0      0      0    29105      0      0      0 LRU
vnet0      1500   0        0      0      0      0        1      0      0      0 BMRU

As far as I can see, it seems vnet0 doesn't forward its trafic to br0 like there's no link.
I have also seen that the vnet0 interface seen from host (opposed to guest) doesn't have the MAC address asked for vnet0, but this may be normal.


--
Fabien