Hi, I'm testing mirroring in ceph and dealt with very slow mirroring operation, Cluster A (primary) is on a Ceph hyperconverged on proxmox and cluster B (secondary) is a Ceph cluster managed by cephadm. These 2 have been peered via bootstrap. Moving 60 GiB VM to the mirrored pool in cluster A it took 5-6 hours to fully sync in the cluster B (SSD device only) Moving 60 GiB VM from cluster A to cluster B in replica 3 SSD pool took 2 minutes (SSD device only) It looks like for this purpose cluster wont be higher than 6-7 MiB/s, is this a normal behaviour ? Ceph -s during mirroring output and rbd info below ceph -s cluster: id: ID health: HEALTH_OK services: mon: 3 daemons, quorum r620-13-1,r620-13-9,r620-13-4 (age 12d) mgr: r620-13-7.zxzajo(active, since 24h), standbys: r620-13-10.wmzodp mds: 1/1 daemons up osd: 24 osds: 24 up (since 6d), 24 in (since 6d) rbd-mirror: 1 daemon active (1 hosts) rgw: 1 daemon active (1 hosts, 1 zones) data: volumes: 1/1 healthy pools: 16 pools, 1287 pgs objects: 151.21k objects, 551 GiB usage: 1.6 TiB used, 6.3 TiB / 7.9 TiB avail pgs: 1287 active+clean io: client: 15 KiB/s rd, 6.5 MiB/s wr, 11 op/s rd, 419 op/s wr -------------------------------------------- rbd info ceph_proxmox/vm-118-disk-0 rbd image 'vm-118-disk-0': size 60 GiB in 15360 objects order 22 (4 MiB objects) snapshot_count: 0 id: abe8c560f69498 block_name_prefix: rbd_data.abe8c560f69498 format: 2 features: layering, exclusive-lock, object-map, fast-diff, deep-flatten, journaling op_features: flags: create_timestamp: Wed Oct 22 07:52:31 2025 access_timestamp: Wed Oct 22 07:52:31 2025 modify_timestamp: Wed Oct 22 07:52:31 2025 journal: abe8c560f69498 mirroring state: enabled mirroring mode: journal mirroring global id: id mirroring primary: false ----------------------------------------- In cluster A ceph.conf rbd_default_features = 125 Thanks ! Vivien