# ceph-volume lvm prepare --bluestore --data /dev/ceph/osd --block.db cas/rocksdb --block.wal cas/waldb
Running command: /usr/bin/ceph-authtool --gen-print-key
Running command: /usr/bin/ceph --cluster ceph --name client.bootstrap-osd --keyring /var/lib/ceph/bootstrap-osd/ceph.keyring -i - osd new 7e50d522-b31d-42a6-9b3a-49f92cae2d25
 stderr: [errno 2] error connecting to the cluster
-->  RuntimeError: Unable to create a new OSD id

cephのキーが無いので、authキーをおいてあげればOK

# ceph auth get client.bootstrap-osd
exported keyring for client.bootstrap-osd
[client.bootstrap-osd]
	key = AQAwT4de6ScSGBAAVohPwCT6irmyVH0PrnUT/A==
	caps mon = "allow profile bootstrap-osd"

# ceph auth get client.bootstrap-osd > /var/lib/ceph/bootstrap-osd/ceph.keyring