> After reading and understanding your mail, i moved on to do some experiments > regarding deep flatten. some questions showed up: > here is my experiement: > ceph version I used: ceph -v output: > ceph version 9.1.0-299-g89b2b9b > 1. create a separate pool for test: > rados mkpool pool100 > 2. create parent image with deep-flatten feature: > rbd create --image-feature deep-flatten --image-feature layering -p pool100 > user1_image1 --size 1024 --image-format 2 > 3. create snap: > rbd snap create pool100/user1_image1@user1_image1_snap > 4. protect snap: > rbd snap protect pool100/user1_image1@user1_image1_snap > 5. clone child image based on this snap: > rbd clone pool100/user1_image1@user1_image1_snap pool100/user1_image2 > 6. create snap on clone image: > rbd snap create pool100/user1_image2@user1_image2_snap > 7. flatten the clone image: > rbd flatten pool100/user1_image2 > test output: > rbd info pool100/user1_image2 > rbd image 'user1_image2': > size 1024 MB in 256 objects > order 22 (4096 kB objects) > block_name_prefix: rbd_data.1016317b2d6 > format: 2 > features: layering <==== why after flatten, cloned image is without > deep-flatten feature? > flags: 'rbd clone' doesn't copy features from the parent image -- you needed to specify "--image-feature deep-flatten" when creating the clone. > rbd info pool100/user1_image2@user1_image2_snap > rbd image 'user1_image2': > size 1024 MB in 256 objects > order 22 (4096 kB objects) > block_name_prefix: rbd_data.1016317b2d6 > format: 2 > features: layering > flags: > protected: True > parent: pool100/user1_image1@user1_image1_snap <==== why after flatten, child > snapshot still has parent snap info? > overlap: 1024 MB Because deep-flatten wasn't enabled on the clone. > Another question is since deep-flatten operations are applied to cloned > image, why we need to create parent image with deep-flatten image features?? The deep-flatten feature is not required on the parent image (since non-cloned images cannot be flattened). > Cory -- Jason Dillaman _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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