:lastproofread: 2025-11-14

.. _boot-options:


############
Boot Options
############

.. warning:: This function can disrupt services.
   Run it only when necessary, and verify all input values before proceeding.


VyOS provides several kernel command-line options to modify the normal boot
process.
To add an option, select the desired image in the GRUB menu at load time.
Type **e** to edit the first line, then type **Ctrl+X** to boot.

.. image:: /_static/images/boot-options.png
   :width: 80%
   :align: center


Specify custom config file
==========================

You can use a configuration file instead of the default ``/config/config.boot``
file.
If the specified file doesn't exist or isn't readable, the system uses the
default configuration file.
No additional verification is performed, so specify a valid configuration file.

.. code-block:: none

   vyos-config=/path/to/file

To load the *factory default* configuration, use:

.. code-block:: none

   vyos-config=/opt/vyatta/etc/config.boot.default


Disable specific boot process steps
===================================

These options disable certain steps in the boot process. Understand the
:ref:`boot process <boot-steps>` before using them.

.. glossary::

    no-vyos-migrate
      Do not perform config migration.

    no-vyos-firewall
      Do not initialize default firewall chains, renders any firewall
      configuration unusable.