This is the formula I use to setup RADOS test clusters on a single host. This is in addition to the method, which is also a very useful tool.

export DATA_DEV=sdb
export JRNL_DEV=sdc
ceph-deploy install --stable emperor kyoto
ceph-deploy pkg --install librados-dev kyoto
ceph-deploy new kyoto
echo "osd crush chooseleaf type = 0" >> ceph.conf
echo "osd pool default size = 1" >> ceph.conf
ceph-deploy mon create-initial kyoto
ceph-deploy disk zap kyoto:$DATA_DEV
ceph-deploy disk zap kyoto:$JRNL_DEV
ceph-deploy osd create kyoto:$DATA_DEV:$JRNL_DEV
sudo chmod +r /etc/ceph/ceph.client.admin.keyring