From Fedora Project Wiki

Ignore Anaconda kernel boot parameters without 'inst.' prefix


Right now Anaconda allows usage of boot options both with the 'inst' prefix (inst.stage2=) and without (stage2=). We would like to ignore the use of Anaconda kernel boot parameters which do not contain the 'inst.' prefix.


Current status

Detailed Description

Anaconda allows you to use kernel boot parameters with and without the 'inst.' prefix right now (e.g. inst.repo= / repo=). However, specifying boot parameters without the 'inst' prefix has not been recommended for years and has been deprecated since Fedora 33. We (Anaconda team) would like to make it an official requirement now that users must specify the 'inst.' prefix all the time.

The reason for this is frequent parameter conflicts with other projects. We already had a few issues with conflicts in the past, such as if the user ran an installation with debug. In that case the installation boot would enable debug mode for the kernel and also for Anaconda which is probably not what the user intended. Another reason is to make it readable at first glance what belongs to Dracut (rd.), kernel (no prefix) or Anaconda (inst.).


We have sent mail about doing the deprecation on Fedora 33. The only issue there was why the prefix is 'inst.' and not 'anaconda.'.

Benefit to Fedora

This change should make crystal clear what kernel boot parameters are processed by the Anaconda installer. It will also avoid conflicts with other kernel boot parameters.


  • Proposal owners:

Remove support to process arguments without the 'inst.' prefix and require the 'inst.' prefix for kernel boot parameters consumed by Anaconda.

  • Other developers:

All configurations using the not-recommended solution without prefix will have to change the invocation of the kernel boot options consumed by Anaconda. These users are already warned since Fedora 33 after boot. This should not be a problem for ISOs we ship because they already use the recommended 'inst.' prefix everywhere. However, it will probably touch some custom PXE configurations and other custom ISO configurations which are prone to this, because users often want to save typing and not explicitly write the 'inst.' prefix. Fortunately, most of these configuration changes shouldn't be that hard to change.

  • Release engineering: #9889
  • Policies and guidelines:

This should not be required. All the documentation should use the recommended 'inst.' prefix already.

  • Trademark approval: No (not needed for this Change)
  • Alignment with Objectives: No

Upgrade/compatibility impact

If your custom infra configuration is not updated then new Fedora installations could not install correctly. Most probably the ISO will not boot (use of 'stage2=') or your repositories won't be used (use of 'repo=').

How To Test

  1. You need a Virtual Machine and ISO for testing.
  2. Boot the installation using the ISO and try Anaconda specific kernel boot parameters. See here to find out the list
  3. Parameters without the prefix should be ignored and with the prefix should be used.

User Experience

Users of Fedora official ISOs should not be impacted because all the Fedora official ISOs should already use the recommended prefix.


Don't know about any packages impacted by this change.

Contingency Plan

  • Contingency mechanism: The Anaconda team will revert code changes and get back support for boot parameters without the 'inst.' prefix.
  • Contingency deadline: Final Freeze
  • Blocks release? No
  • Blocks product? This won't require changes for any specific product.


I don't think we need to document this change other than in Release Notes. As mentioned before, the solution without 'inst.' prefix has not been recommended for years and it should not be used anywhere in the official documentation.

Release Notes