[ceph] cleanup device class in case something old exists

ceph-osd-create-start

@@ -94,6 +94,9 @@ else
 fi
 
 ceph osd crush add osd.${osd_id} ${WEIGHT} host=$(hostname)
+
+# Ensure previous assigned class is gone
+ceph osd crush rm-device-class osd.${osd_id}
 ceph osd crush set-device-class $CLASS osd.${osd_id}
 
 echo "$metadata_dev /var/lib/ceph/osd/ceph-${osd_id} xfs noatime 0 0" >> /etc/fstab