Comment 0 for bug 724601

Binary package hint: cloud-init

Persistent interface naming should be disabled in UEC images, as it causes more harm that good.

Firstly, cloud systems generally expect the interfaces to be created in the order they are created in the hypervisor. Renaming them (particularly when some images are persistent, and some are not) is confusing.

Secondly, it causes inconsistency, in that the Xen pv interfaces (for instance) are ignored, whereas the kvm ones aren't.

Thirdly, it causes terrible problems (read unbootable machines) on old Xen (and perhaps newer Xen), where the same interface appears twice - once as an emulated HVM interface, and one as a PV on HVM interface each with the same MAC address. That makes for confusion, particularly given one subsystem is ignored and one isn't. Essentially the interfaces constantly rename.

The (very easy) solution is to disable persistent net interface renaming.