Dear Cepher, My client has 10 volume, each volume was assigned 8192 PGs, in total 81920 PGs. The ceph is with Luminous Bluestore. During a power outage, the cluster restarted, and we observed that OSD peering consumed a lot of CPU and memory resources, evne leading to some OSD flappings. My question is thus, 1) how to speed up OSD peering and avoid OSD flappings when there are a lot PGs in the Ceph cluster, and 2) Is there a practical limit on the number of PGs for a single cluster? best regards, Samuel huxiaoyu(a)horebdata.cn