• Contenu
• Cluster with libvirt
  • Fontionnement
  • Migration from Openstack

Cluster with libvirt¶

Fontionnement¶

Les VM utilisent le mode ethernet de libvirt. En gros libvirt s'attends à trouver un tap tout près pour y accrocher la VM

Just avant le boot de la VM libvirt lance:

 /etc/libvirt/hooks/qemu <VM_NAME> prepare begin

Et juste après l'arret de la VM libvirt lance:

 /etc/libvirt/hooks/qemu <VM_NAME> release end

Le script /etc/libvirt/hooks/qemu de ttnn se trouve ici: https://chiliproject.tetaneutral.net/projects/git-tetaneutral-net/repository/puppetmaster/revisions/master/entry/environments/production/manifests/files/openstack/libvirt-hooks-qemu

Ce script va lire les metadatas TTNN de <VM_NAME> (e.g: virsh metadata <VM_NAME> http://tetaneutral.net/)

$ virsh metadata ns2.tetaneutral.net http://tetaneutral.net/
<config>
  <tap name="tapb0b4a106-d0">89.234.156.248</tap>
  <tap name="tapabababab-aa">89.234.156.45</tap>
</config>

Ensuite il va créé le tap et configurer les routes dessus avec les infos des metadata.

Migration from Openstack¶

• virsh dumpxml $id > myvm.xml

• delete VM in openstack
  on openstack.t server:

    $ mysql nova -e "update instances set deleted=1 where display_name = 'ns2.tetaneutral.net';" 
    

• edit myvm.xml * change name to <my_new_name> * remove uuid on top and uuid in sysinfo/system/entry[name=uuid] * change domain/devices/interface/@type == ethernet (instead of bridge) * remove <bridge ***> in domain/devices/interface * On top in metadata add (tap names is located in domain/devices/interface/@type):

     <ttnn:config xmlns:ttnn="http://tetaneutral.net/">
       <ttnn:tap name="tapb0b4a106-d0">89.234.156.248</ttnn:tap>
     </ttnn:config>
    

  (IP can be found on djadhere or g1:/root/sileht/debug/nova_list)
• On top in metadata remove <nova:instance ...></nova:instance> section

• virsh destroy $id
• virsh undefine $id
• virsh define myvm.xml
• virsh start <my_new_name>