[libvirt] How to avoid the disk still persistent after no persistent hotplug and with restarting libvirtd then.

Libvirt loads the domain conf from the status file (/var/run/libvirt/qemu/$dom.xml) if the domain is running, the problem if one restart libvirtd just after some changing on the domain conf, and then destroy/start the guest. libvirt will never known what the original domain conf is then. (vm->newdef is NULL at this moment, generally libvirt restore the domain conf to the original conf (vm->newDef) when destroying and shutdown). Following is a demo of the problem: 1) hotplug a disk to a running domain without "--persistent" specified. 2) restart libvirtd 3) Destroy/start the guest 4) you will see the hotpluged disk is still there. The solution in my mind is to add some attribute to the status XML, such as "live_updated=1", and do the checking when loading the domain conf from status XML: * if "live_updated=1", then loads the domain conf from the persistent domain XML. But the problem is: For a persistent domain, if one made changes on the domain conf both persistently and transiently, we have no way to known which part are changed. Loading from the persistent domain conf is not correct either. For a transient domain, we still have no way to get the original domain conf, that means one will still be surprised when seeing the the disk is still there. Any idea on this? Thanks Osier