Hello! Few years ago I build a "dc-a:12 + dc-b:12 = 24" node ceph cluster with Nautilus v14.2.16 A year ago the cluster upgraded to Octopus and it was running fine. Recently I added 4+4=8 new nodes with identical hardware and SSD drives. When I created OSD's with Octopus, The cluster usage increased from %50 to %78!! The weird problem is, the new OSD's become nearfull and hold more size even if they have the same or less amount of PG's. I had to reweight new OSD's to 0.9 to make them equal size usage.. I increased the PG count 8192 to 16384 and ran balancer, it became worse and I have %84 usage now! I guess OSD or PG code changed between nautilus <-> octopus and it generates this problem. Can anyone help me with experience or knowledge about this? What should I do? My solution idea: I'm thinking of destroy and re-create old OSD's as a solution but I need to re-create 144x3.8TB Sas SSD OSD's and it means 4-5 days of maintenance. Also I have 2 osd per drive because it was recommended at Nautilus times. How about this? Should I keep the config or should I use 1 osd per 3.8TB SAS SSD ? What is the recommendation for Octopus and Quincy? - Best regards.