By *taking over* management, it disables all ``ceph-disk`` systemd units used
to trigger devices at startup, relying on basic (customizable) JSON
configuration and systemd for starting up OSDs.
+
+This process involves two steps:
+
+#. :ref:`Scan <ceph-volume-simple-scan>` the running OSD or the data device
+#. :ref:`Activate <ceph-volume-simple-activate>` the scanned OSD
+
+The scanning will infer everything that ``ceph-volume`` needs to start the OSD,
+so that when activation is needed, the OSD can start normally without getting
+interference from ``ceph-disk``.
+
+As part of the activation process the systemd units for ``ceph-disk`` in charge
+of reacting to ``udev`` events, are linked to ``/dev/null`` so that they are
+fully inactive.