I am using centos 7 and I am trying to configure grub password protection, when using pbkdf2 encryption everything is ok but using plain text password it does not work. I have taken care of syntax and use the mkconfig tool to replace the grub.conf but still nothing. Have anyone succeeded with this configuration?, I know that encrypted passwords is a best practice but I want to have the whole picture. Please find below my config used, the file /etc/grub.d/01_users:
cat <<EOF
set superusers="main"
password main mainpass
password user1 user1pass
EOF