Hi, I have the following Ceph Mimic setup : - a bunch of old servers with 3-4 SATA drives each (74 OSDs in total) - index/leveldb is stored on each OSD (so no SSD drives, just SATA) - the current usage is : GLOBAL: SIZE AVAIL RAW USED %RAW USED 542 TiB 105 TiB 437 TiB 80.67 POOLS: NAME ID USED %USED MAX AVAIL OBJECTS .rgw.root 1 1.1 KiB 0 26 TiB 4 default.rgw.control 2 0 B 0 26 TiB 8 default.rgw.meta 3 20 MiB 0 26 TiB 75357 default.rgw.log 4 0 B 0 26 TiB 4271 default.rgw.buckets.data 5 290 TiB 85.05 51 TiB 78067284 default.rgw.buckets.non-ec 6 0 B 0 26 TiB 0 default.rgw.buckets.index 7 0 B 0 26 TiB 603008 - rgw_override_bucket_index_max_shards = 16. Clients are accessing RGW via Swift, not S3. - the replication schema is EC 4+2. We are using this Ceph cluster as a secondary storage for another storage infrastructure (which is more expensive) and we are offloading cold data (big files with a low number of downloads/reads from our customer). This way we can lower the TCO . So most of the files are big ( a few GB at least). So far Ceph is doing well considering that I don't have big expectations from current hardware. I'm a bit worried however that we have 78 M objects with max_shards=16 and we will probably reach 100M in the next few months. Do I need a increase the max shards to ensure the stability of the cluster ? I read that storing more than 1 M of objects in a single bucket can lead to OSD's flapping or having io timeouts during deep-scrub or even to have ODS's failures due to the leveldb compacting all the time if we have a large number of DELETEs. Any advice would be appreciated. Thank you, Adrian Nicolae