2.11.1. Chroot Environment
To run the post-installation script outside of the chroot environment, click the checkbox next to this option on the top of the Post-Installation window. This is equivalent to using the --nochroot option in the %post section.
To make changes to the newly installed file system, within the post-installation section, but outside of the chroot environment, you must prepend the directory name with /mnt/sysimage/.
For example, if you select Run outside of the chroot environment, the previous example must be changed to the following:
echo "Hackers will be punished!" > /mnt/sysimage/etc/motd