Hi, I tried to run this command with failure: root@ld3955:/mnt/rbd# ceph osd set-require-min-compat-client luminous Error EPERM: cannot set require_min_compat_client to luminous: 6 connected client(s) look like jewel (missing 0xa00000000200000); 19 connected client(s) look like jewel (missing 0x800000000000000); 23 connected client(s) look like jewel (missing 0x800000000000000); add --yes-i-really-mean-it to do it anyway root@ld3955:/mnt/rbd# ceph features { "mon": [ { "features": "0x3ffddff8ffacffff", "release": "luminous", "num": 3 } ], "mds": [ { "features": "0x3ffddff8ffacffff", "release": "luminous", "num": 2 } ], "osd": [ { "features": "0x3ffddff8ffacffff", "release": "luminous", "num": 368 } ], "client": [ { "features": "0x40106b84a842a42", "release": "jewel", "num": 6 }, { "features": "0x27018eb84aa42a52", "release": "jewel", "num": 19 }, { "features": "0x27018fb86aa42ada", "release": "jewel", "num": 23 }, { "features": "0x3ffddff8ffacffff", "release": "luminous", "num": 35 } ], "mgr": [ { "features": "0x3ffddff8ffacffff", "release": "luminous", "num": 3 } ] } But I think the number of clients older than Luminous is incorrect. I'm running 98% of the clients with SLES 12SPx, and therefore the question is: Can you confirm in which SLES 12 release the function upmap is supported? And is it safe to execute ceph osd set-require-min-compat-client luminous --yes-i-really-mean-it? What happens to the clients then? Regards Thomas