Read this if you clone machines, virtual or not.
I experienced some trouble when cloning machines with the nice ghost for linux (g4l).
On the cloned machines, eth0 becomes eth1. So network config don't work as expected.
Changing network card modules aliases do nothing !
It's because of udev.
Take a look at /etc/udev/rules.d/75-network-devices.rules
(the number may change with distro).
Those parameters are persistant so we need to delete it.
Well the last time we stop the master machine before cloning.
According to a friend, these persistent options in /etc/udev/rules.d/ may lead to another exotic problems.