Ceph » rbd

- how parent images are marked read-only
- how parent/child relationship is represented
- possibly how this allows parent image read-only-ness to be enforced via osd caps?
- read path
- write path
- copy-up process, atomicity/safety thereof
- rbd tool/user experience

- keep in mind future optimizations:
- object and image bitmaps to limit fall-thru checks, iterating over non-existent objects. see http://marc.info/?l=ceph-devel&m=129867273303846