When handling a Ceph OSD, it is convenient to assign it a symbolic name that can be chosen even before it is created. That’s what the uuid argument for ceph osd create is for. Without a uuid argument, a random uuid will be assigned to the OSD and can be used later. Since the ceph osd create uuid is idempotent, it can also be used to lookup the id of a given OSD.
$ osd_uuid=b2e780fc-ec82-4a91-a29d-20cd9159e5f6 # convert the OSD uuid into an OSD id $ ceph osd create $osd_uuid 0 # convert the OSD id into an OSD uuid $ ./ceph --format json osd dump | jq '.osds[] | select(.osd==0) | .uuid' "b2e780fc-ec82-4a91-a29d-20cd9159e5f6"