Hello Cephers, On a capacitive Ceph cluster (13 nodes, 130 OSDs 8To HDD), I'm migrating a 40 To image from a 3+2 EC pool to a 8+2 one. The use case is Veeam backup on XFS filesystems, mounted via KRBD. Backups are running, and I can see 200MB/s Throughput. But my migration (rbd migrate prepare / execute) is staling at 4% for 6h now. When the backups are not running, I can see a little 20MB/s of throughput, certainly my migration. I need a month to migrate 40 to at that speed ! As I use a KRBD client, I cannot remap the rbd image straight after the rbd prepare. So the filesystem is not usable until the migration is completed. Not really usable for me... Is anyone has a clue either to speed up the rbd migration, or another method to move/copy an image between 2 pools, with the minimum downtime ? I thought of rbd export-diff | rbd import-diff, while mounted, and another unmapped before switching... But, it forces me to rename my image, because if I use another data pool, the metadata pool stays the same. Can you see another method ? -- Gilles