[libvirt-users] which is the config file for a vm ?

[Lentes, Bernd]

Hi, 

i have a weird problem. I have a vm (KVM) which seems to run fine. I believe the respective config file for this vm is /etc/libvirt/qemu/MausDB.xml. This is it:

=========================================================
<domain type='kvm'>
  <name>MausDB</name>
  <uuid>d4c7956c-b57f-967a-0454-99835a3a740b</uuid>
  <memory unit='KiB'>2353792</memory>
  <currentMemory unit='KiB'>2353792</currentMemory>
  <vcpu placement='static'>2</vcpu>
  <os>
    <type arch='x86_64' machine='pc-i440fx-1.4'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <pae/>
  </features>
  <clock offset='utc'/>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <devices>
    <emulator>/usr/bin/qemu-kvm</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw'/>
      <source file='/var/lib/kvm/images/MausDB/disk0.raw'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <target dev='hda' bus='ide'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <controller type='usb' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
    </controller>
    <controller type='pci' index='0' model='pci-root'/>
    <controller type='ide' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <interface type='bridge'>
      <mac address='52:54:00:37:92:03'/>
      <source bridge='br0'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes'/>
    <video>
      <model type='cirrus' vram='9216' heads='1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </video>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </memballoon>
  </devices>
</domain>
=============================================================

As you see, the vm has one NIC. Its MAC-Address is: '52:54:00:37:92:03'.
I also see that MAC when i edit the config via virsh.

But when i boot that vm, it has a nic with another MAC: '52:54:00:37:92:B2' ??? lspci shows me just one nic in the vm.
This MAC-Address is also visible in the Virtual Machine Manager.
Pictures you find here: https://hmgubox.helmholtz-muenchen.de:8001/d/51feb02c02/ 
I thought the xml-file in /etc/libvirt/qemu ist the only responsable one. It is that one which is configured when i issue a 'edit domain' in virsh. Or ?
Where does the VMM stores the configuration of the domains ?
I found another xml: /var/run/libvirt/qemu/MausDB.xml . Inside it there is the MAC the booted vm has. What is the purpose of this xml ?
Also ps inside the host shows the MAC which is in the booted vm:

root     28237  4.8  2.4 2886084 2416116 ?     Sl   Feb29  55:16 /usr/bin/qemu-kvm -name MausDB -S -machine pc-i440fx-1.4,accel=kvm,usb=off -m 2299 -smp 2,sockets=2,cores=1,threads=1 -uuid d4c7956c-b57f-967a-0454-99835a3a740b -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/MausDB.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -boot strict=on -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/var/lib/kvm/images/MausDB/disk0.raw,if=none,id=drive-virtio-disk0,format=raw -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -drive if=none,id=drive-ide0-0-0,readonly=on,format=raw -device ide-cd,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0 -netdev tap,fd=22,id=hostnet0,vhost=on,vhostfd=23 -device virtio-net-pci,netdev=hostnet0,id=net0,     mac=52:54:00:37:92:b2,bus=pci.0,addr=0x3 -vnc 127.0.0.1:0 -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x5


Can anyone help sorting this out ?


Bernd

-- 
Bernd Lentes 

Systemadministration 
institute of developmental genetics 
Gebäude 35.34 - Raum 208 
HelmholtzZentrum München 
bernd.lentes at helmholtz-muenchen.de 
phone: +49 (0)89 3187 1241 
fax: +49 (0)89 3187 2294 

Wer Visionen hat soll zum Hausarzt gehen 
Helmut Schmidt
 

Helmholtz Zentrum Muenchen
Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH)
Ingolstaedter Landstr. 1
85764 Neuherberg
www.helmholtz-muenchen.de
Aufsichtsratsvorsitzende: MinDir'in Baerbel Brumme-Bothe
Geschaeftsfuehrer: Prof. Dr. Guenther Wess, Dr. Alfons Enhsen, Renate Schlusen (komm.)
Registergericht: Amtsgericht Muenchen HRB 6466
USt-IdNr: DE 129521671