Cannot delete snapshot due to hidden differencing image
Fairly regularly, I find that when I try to delete a snapshot, the VBM (VBox Manager) reports that it cannot because there is more than one child hard disk. However, the VBM does not show any indication of its existence in the snapshot hierarchy. I can only see the extra disk in the VMM (VMedia Manager), where I can delete it and then successfully delete the snapshot from the VBM.
However, that the VBM and VMM disagree about the disk/differencing hierarchy must be a bug, right?
In all of the situations where this has occurred, I have done nothing more complex than periodically create snapshots and periodically delete them. The disks are not shared across machines and I've not cloned any machines. Unfortunately, it's not reproducible, it just occasionally happens. I've come across this problem on 2 different hosts with 4.1.4. I think I've seen it in earlier versions too.