On 6/11/19 3:24 PM, Rafael Diaz Maurin wrote: > 3- I create a snapshot inside the source pool > rbd snap create ${POOL-SOURCE}/${KVM-IMAGE}@${TODAY-SNAP} > > 4- I export the snapshot from the source pool and I import the snapshot > towards the destination pool (in the pipe) > rbd export-diff --from-snap ${LAST-SNAP} > ${POOL-SOURCE}/${KVM-IMAGE}@${TODAY-SNAP} - | rbd -c ${BACKUP-CLUSTER} > import-diff - ${POOL-DESTINATION}/${KVM-IMAGE} Here, you are wrong If have to export-diff (without --from-snap) to do the "first" export What you are doing is rebasing the image, on the backup cluster, based on crap (the dummy snapshot you created on step 3) So: 1) Create a snapshot of source image 2) Create a dest image if not exists 3) If dest was created, export the source snapshot and import it: rbd export-diff <image> --snap <snap> | rbd import-diff - <dest-image> 3b) If dest was not created (you then have a shared snapshot between the source and the dest), export-diff using from-snap: rbd export-diff --from-snap <snap1> <image> --snap <snap2> | rbd import-diff - <dest-image> You can checkout Backurne's code, that does what you want: https://github.com/JackSlateur/backurne/blob/master/ceph.py#L173 Best regards, > > The problem occurs when I want to validate only the diff between the 2 > snapshots (in order to be more efficient). I note that those hashes are > differents. > > Here is how I calcultate the hashes : > Source-hash : rbd diff --from-snap ${LAST-SNAP} > ${POOL-SOURCE}/${KVM-IMAGE}@${TODAY-SNAP} --format json | md5sum | cut > -d ' ' -f 1 > => bc56663b8ff01ec388598037a20861cf > Destination-hash : rbd -c ${BACKUP-CLUSTER} diff --from-snap > ${LAST-SNAP} ${POOL-DESTINATION}/${KVM-IMAGE}@${TODAY-SNAP} --format > json | md5sum | cut -d ' ' -f 1 > => 3aa35362471419abe0a41f222c113096 > > In an other hand, if I compare the hashes of the export (between source > and destination), they are the same : > > rbd -p ${POOL-SOURCE} export ${KVM-IMAGE}@${TODAY-SNAP} - | md5sum > => 2c4962870fdd67ca758c154760d9df83 > rbd -c ${BACKUP-CLUSTER} -p ${POOL-DESTINATION} export > ${KVM-IMAGE}@${TODAY-SNAP} - | md5sum > => 2c4962870fdd67ca758c154760d9df83 > > > Can someone has an idea of what's happenning ? > > Can someone has a way to succeed in comparing the export-diff > /import-diff ? > > > > > Thank you, > Rafael > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com