Fedora LiveDVD ignores given boot options to setup keyboard layout

edit

when i boot Fedora 27 LiveDVD and modify the boot options to use an other keyboard layout and user interface language, those parameters are completely ignored.

1'st, boot the PC from an Fedora27 LiveDVD (Fedora-Workstation-Live-x86_64-27-1.6.iso)

2'nd, and modify the boot option in the boot menu by hitting [TAB]:

3'rd, add at the end

rd.vconsole.keymap=de-latin1-nodeadkeys

and

rd.locale.LANG=de_DE.utf8

as shown in the dracut man pages dracut - I18N.

but when Fedora is fully booted into the UI, the language is still "en_US" and the keyboard is "en" as well.

for the keyboard layout i also tried:

rd.vconsole.keymap=de
vconsole.keymap=de
keymap=de
inst.keymap=de

for the UI language similar:

rd.locale.LANG=de_DE
locale.LANG=de_DE
lang=de_DE
inst.lang=de_DE

all without success.

any idea, how i can change keyboard layout and UI language of Fedora LiveDVD via boot options?