Clone Guests from Template Image


   virsh shutdown basevm

dump its XML file to template.xml and copy its image to template.qcow2

   virsh dumpxml basevm > /var/lib/libvirt/images/template.xml
   cp /var/lib/libvirt/images/basevm.qcow2 /var/lib/libvirt/images/template.qcow2

in template.xml point the disk source file to template.qcow2

<disk type='file' device='disk'>
  <driver name='qemu' type='qcow2' cache='none'/>
  <source file='/var/lib/libvirt/images/template.qcow2'/>
  <target dev='vda' bus='virtio'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>

run virt-sysprep on template.qcow2.

This will reset the image, e.g. will remove the host SSH keys, will create new MAC address for network interfaces, adjust udev persistent net rules, clean up log files, etc...

   virt-sysprep -a /var/lib/libvirt/images/template.qcow2

after this poin you don't need the base VM anymore. Delete it.

   virsh undefine basevm
   rm /var/lib/libvirt/images/basevm.qcow2

Cloning new VMs from Template

   clone new VMs from template.xml and template.qcow2
   virt-clone --connect qemu:///system                    \
     --original-xml /var/lib/libvirt/images/template.xml  \
     --name newvm                                         \
     --file /var/lib/libvirt/images/newvm.qcow2