.. _ceph-volume-simple:

``simple``
==========
Implements the functionality needed to manage OSDs from the ``simple`` subcommand:
``ceph-volume simple``

**Command Line Subcommands**

* :ref:`ceph-volume-simple-scan`

* :ref:`ceph-volume-simple-activate`

* :ref:`ceph-volume-simple-systemd`


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.