Hi all, We noticed that changing existing pools from being class-agnostic to choose a class (e.g. hdd [1]) then a lot, perhaps all, data will move. I think this is because the crush IDs in the shadow tree are too different, or maybe just a different order, from the original bucket IDs. But I wonder if we could use `ceph osd crush swap-bucket` (or a more elaborate version of swap bucket) to move the shadow buckets into the correct place in the tree, thereby preventing data movement. Did anyone already ponder on this topic? Cheers, Dan [1] https://ceph.com/community/new-luminous-crush-device-classes/ _______________________________________________ Ceph-large mailing list Ceph-large@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-large-ceph.com
