Snapshots are read-only, so all changes to the image can only be applied to the HEAD revision.
In general, you should take a snapshot prior to export / export-diff to ensure consistent images: rbd snap create rbd/small@snap1 rbd export rbd/small@snap1 ./foo rbd import ./foo backup/small rbd snap create backup/small@snap1 ** rbd/small and backup/small are now consistent through snap1 -- rbd/small might have been modified post snapshot rbd snap create rbd/small@snap2 rbd export-diff --from-snap snap1 rbd/small@snap2 ./foo.diff rbd import-diff ./foo.diff backup/small ** rbd/small and backup/small are now consistent through snap2. import-diff automatically created backup/small@snap2 after importing all changes. -- Jason Dillaman Red Hat dilla...@redhat.com http://www.redhat.com ----- Original Message ----- From: "Steve Anthony" <sma...@lehigh.edu> To: ceph-users@lists.ceph.com Sent: Tuesday, March 3, 2015 2:06:44 PM Subject: [ceph-users] import-diff requires snapshot exists? Hello, I've been playing with backing up images from my production site (running 0.87) to my backup site (running 0.87.1) using export/import and export-diff/import-diff. After initially exporting and importing the image (rbd/small to backup/small) I took a snapshot (called test1) on the production cluster, ran export-diff from that snapshot, and then attempted to import-diff the diff file on the backup cluster. # rbd import-diff ./foo.diff backup/small start snapshot 'test1' does not exist in the image, aborting Importing image diff: 0% complete...failed. rbd: import-diff failed: (22) Invalid argument This works fine if I create a test1 snapshot on the backup cluster before running import-diff. However, it appears that the changes get written into backup/small not backup/small@test1. So unless I'm not understanding something, it seems like the content of the snapshot on the backup cluster is of no importance, which makes me wonder why it must exist at all. Any thoughts? Thanks! -Steve -- Steve Anthony LTS HPC Support Specialist Lehigh University sma...@lehigh.edu _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
