.. highlight:: console
.. _Running:

*******
Running
*******

The Knot DNS server part ``knotd`` can run either in the foreground or in the background,
with the ``-d`` option. When run in the foreground, it doesn't create a PID file.
Other than that, there are no differences and you can control it just the same way.

The tool ``knotc`` is designed as a front-end for user, making it easier to control running
server daemon. If you want to control the daemon directly, use ``SIGINT`` to quit
the process or ``SIGHUP`` to reload configuration.

If you pass neither configuration file (``-c`` parameter) nor configuration
database (``-C`` parameter), server will try to use the default configuration
file stored in ``SYSCONFDIR/knot/knot.conf`` (configured with
``--with-configdir=path``)

Example of server start as a daemon::

    $ knotd -d -c knot.conf

Example of server stop::

    $ knotc -c knot.conf stop

For a complete list of actions refer to ``knotd -h`` and ``knotc -h``
or corresponding man pages.

Also, the server needs to create :ref:`server_rundir` and :ref:`zone_storage`
directories in order to run properly.

.. _Configuration database:

Configuration database
======================

In the case of a huge configuration file, the configuration can be preloaded
into the server`s configuration database::

    $ knotc import input.conf

Also the configuration database can be exported into the configuration file::

    $ knotc export output.conf

It is recommended to process these operations without server running.

.. _Running a slave server:

Running a slave server
======================

Running the server as a slave is very straightforward as you usually
bootstrap zones over AXFR and thus avoid any manual zone operations.
In contrast to AXFR, when the incremental transfer finishes, it stores
the differences in the journal file and doesn't update the zone file
immediately but after :ref:`zone_zonefile-sync` period elapses.

.. _Running a master server:

Running a master server
=======================

If you want to just check the zone files first before starting, you
can use ``knotc checkzone`` action::

    $ knotc -c master.conf checkzone example.com

For an approximate estimate of server's memory consumption, you can
use the ``knotc memstats`` action. This action prints count of
resource records, percentage of signed records and finally estimation
of memory consumption for each zone, unless otherwise
specified. Please note that estimated values might differ from the
actual consumption. Also, for slave servers with incoming transfers
enabled, be aware that the actual memory consumption might be double
or more during transfers::

    $ knotc -c master.conf memstats example.com

.. _Controlling running daemon:

Controlling running daemon
==========================

Knot DNS was designed to allow server reconfiguration on-the-fly
without interrupting its operation. Thus it is possible to change
both configuration and zone files and also add or remove zones without
restarting the server. This can be done with the ``knotc reload``
action::

    $ knotc -c master.conf reload

If you want to enable ixfr differences creation from changes you make to a
zone file, enable :ref:`zone_ixfr-from-differences` in the zone configuration
and reload your server as seen above. If *SOA*'s *serial* is not changed,
no differences will be created.

If you want to refresh the slave zones, you can do this with the
``knotc refresh`` action::

    $ knotc -c slave.conf refresh

For the zone retransfer, there is also an additional command ``-f``.
