I was running libvirt 1.2.2 and qemu 2.0 which are from icehouse cloud archive repo on ubuntu 12.04, "virsh list --all" showed correct instances after launching several VMs, 

Then I just downgraded libvirt to 0.9.13 and qemu to 1.0, but kept the VMs running. However, when I run "virsh list --all" after downgrade, I can't see any VMs. Seems that the old version libvirt 0.9.13 doesn't know the instances created by libvirt 1.2.2.

Does anyone know how to solve this problem?

Regards,

Chengyuan.