# rbd info precise-rbd257
rbd image 'precise-rbd257':
	size 10240 MB in 2560 objects
	order 22 (4096 KB objects)
	block_name_prefix: rbd_data.17d51f1fab05
	format: 2
	features: layering
	parent: rbd/precise-master@initial
	overlap: 10240 MB

# rbd children precise-master@initial | grep -c precise-rbd257
0

# rbd rm precise-rbd257
Removing image: 99% complete...failed.
delete error: (2) No such file or directory
2012-11-06 12:00:45.490949 7f60bb80a780 -1 librbd: error removing child from children list

# rbd flatten precise-rbd257
Image flatten: 99% complete...failed.
flatten error: (2) No such file or directory
2012-11-06 12:06:13.788567 7fa492714780 -1 librbd: error removing child from children list