How to change download policy of repositories in Red Hat Satellite 6?

This is tricky: you had to (most probably automatically) set a checksum type to the (katello) repos, which prevents them in changing the policy to On Demand (that newly requires no checksum type, dunno why). I think the below rake script can clean the checksum types. It works on 6.9, for older releases, you need to replace pulp_primary by pulp_master:

Katello::RootRepository.yum_type.find_each do |root_repo|
  root_repo.transaction do
    begin
      if [::Runcible::Models::YumImporter::DOWNLOAD_ON_DEMAND, ::Runcible::Models::YumImporter::DOWNLOAD_BACKGROUND].include?(root_repo.download_policy) && root_repo.url.present? && URI(root_repo.url).scheme == 'file'
        root_repo.update_attribute(:download_policy, ::Runcible::Models::YumImporter::DOWNLOAD_IMMEDIATE)
        root_repo.repositories.each do |repo|
          importer = repo.importers[0]
          config = {
            :download_policy => ::Runcible::Models::YumImporter::DOWNLOAD_IMMEDIATE
          }

          SmartProxy.pulp_primary.pulp_api.resources.repository.update_importer(repo.pulp_id, importer[:id], config) if (importer && importer[:id])
        end
      end

      if !root_repo.on_demand? && root_repo.url.present?
        root_repo.update_attribute(:checksum_type, nil)

        root_repo.repositories.each do |repo|
          begin
            repo.update_attribute(:saved_checksum_type, nil)

            if repo.find_distributor[:config]&.delete(:checksum_type)
              SmartProxy.pulp_primary.pulp_api.resources.repository.update_distributor(
                repo.pulp_id, repo.find_distributor[:id], repo.find_distributor[:config])
            end
          # rubocop:disable HandleExceptions
          rescue RestClient::ResourceNotFound
          end
        end
      end
    end
  end
end

Save that as a checksum.rake file, and run: cat checksum.rake | foreman-rake console. THEN re-run the katello:change_download_policy rake script again.

I will ask katello engineering to verify if my script is correct (it quite truly mimics one upgrade script), so please hold on until I confirm it correctness.

Hello, that is a known issue. Please follow this KCS.