Hello Users, We have the environment as below. Both environments are the zones of one RGW multisite zonegroup, whereas the DC zone is the primary and the DR zone is the secondary at this point. DC Ceph Version: 17.2.6 (d7ff0d10654d2280e08f1ab989c7cdf3064446a5) quincy (stable) Number of rgw daemons : 25 DR Ceph Version 17.2.6 (d7ff0d10654d2280e08f1ab989c7cdf3064446a5) quincy (stable) Number of rgw daemons : 25 Environment description: Both the mentioned zones are in production and the RGW multisite bandwidth is over MPLS of around 3 Gbps. Issue description : We have enabled the multisite between DC-DR almost around a month ago. The total data at the DC zone is around 159 TiB and the sync has been going as expected . But when the sync had gone around 120 TiB we saw the speed drastically fell low, the ideal was around 2 Gbps, and it fell way below 10 Mbps though the link is not saturated. After checking "# radosgw-admin sync status " the output says "metadata is caught up with master" and "data is caught up with source" but with almost 25 TB data behind as compared to DC. It also looks like the sync status of the bucket " radosgw-admin bucket sync status --bucket=<bucket-name>" still bucket is behind shards. Attaching the log and the output below. The possibility of issuing a resync of the data from the beginning is quite low and not feasible in our case. The "# radosgw-admin sync error list" output is also attached with some information redacted and we see errors. radosgw-sync status radosgw-admin sync status realm 6a7fab77-64e3-453e-b54b-066bc8af2f00 (realm0) zonegroup be660604-d853-4f8e-a576-579cae2e07c2 (zg0) zone d06a8dd3-5bcb-486c-945b-2a98969ccd5f (fbd) metadata sync syncing full sync: 0/64 shards incremental sync: 64/64 shards metadata is caught up with master data sync source: d09d3d16-8601-448b-bf3d-609b8a29647d (ahd) syncing full sync: 0/128 shards incremental sync: 128/128 shards data is caught up with source radosgw-admin bucket sync status --bucket=<bucket-name> realm 6a7fab77-64e3-453e-b54b-066bc8af2f00 (realm0) zonegroup be660604-d853-4f8e-a576-579cae2e07c2 (zg0) zone d06a8dd3-5bcb-486c-945b-2a98969ccd5f (fbd) bucket :tc******rc-b1[d09d3d16-8601-448b-bf3d-609b8a29647d.38987.1]) source zone d09d3d16-8601-448b-bf3d-609b8a29647d (ahd) source bucket :tc*******arc-b1[d09d3d16-8601-448b-bf3d-609b8a29647d.38987.1]) full sync: 14/9221 shards full sync: 49448693 objects completed incremental sync: 9207/9221 shards bucket is behind on 25 shards behind shards: [9,111,590,826,1774,2968,3132,3382,3386,3409,3685,3820,4174,4544,4708,4811,5733,6285,6558,7288,7417,7443,7876,8151,8878] Error: radosgw-admin sync error list "id": "1_1690799008.725414_3926410.1", "section": "data", "name": "bucket0:d09d3d16-8601-448b-bf3d-609b8a29647d.89871.1:1949", "timestamp": "2023-07-31T10:23:28.725414Z", "info": { "source_zone": "d09d3d16-8601-448b-bf3d-609b8a29647d", "error_code": 125, "message": "failed to sync bucket instance: (125) Operation canceled" "id": "1_1690804503.144829_3759212.1", "section": "data", "name": "bucket1:d09d3d16-8601-448b-bf3d-609b8a29647d.38987.1:1232/S01/1/120/2b7ea802-efad-41d3-9d90-9**************523.txt", "timestamp": "2023-07-31T11:54:53.233451Z", "info": { "source_zone": "d09d3d16-8601-448b-bf3d-609b8a29647d", "error_code": 5, "message": "failed to sync object(5) Input/output error" Thanks Ankit