Hi, I'm using ceph 0.56.6 and kernel 3.9.7 and it looks like modifying RBD image also changes it's snapshot. I can reproduce this as follows: # create and map an image rbd create --size 128 test-1 rbd map test-1 # write some data to the image dd if=/dev/zero of=/dev/rbd/rbd/test-1 bs=1M count=128 # create and map a snapshot rbd snap create test-1@snap-1 rbd map test-1@snap-1 # verify that image and snapshot are identical md5sum /dev/rbd/rbd/test-1 /dev/rbd/rbd/test-1@snap-1 fde9e0818281836e4fc0edfede2b8762 /dev/rbd/rbd/test-1 fde9e0818281836e4fc0edfede2b8762 /dev/rbd/rbd/test-1@snap-1 # modify the image dd if=/dev/urandom of=/dev/rbd/rbd/test-1 bs=512 count=1 # compare checksums again md5sum /dev/rbd/rbd/test-1 /dev/rbd/rbd/test-1@snap-1 1d942c8a5bc7480cecb945ea0d020eed /dev/rbd/rbd/test-1 1d942c8a5bc7480cecb945ea0d020eed /dev/rbd/rbd/test-1@snap-1 Checksums are identical although the snapshot isn't supposed to be modified. -- Karol Jurak -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
