Setting a bucket’s OSD weights
Set all Ceph OSD weights under a bucket by running a single command.
Using the ceph osd crush reweight command can be time-consuming. You can set (or reset) all Ceph OSD weights under a bucket (row, rack, node, and so on) by running the ceph osd crush reweight-subtree command.
ceph osd crush reweight-subtree NAME
Where NAME is the name of the CRUSH bucket.