RHCSA 7 and upstart, init, systemd

Any thoughts on this ? I suppose I just have to learn the lot anyway. But what about the exam ? Thoughts on the whole thing are welcome.
RH7 has sytemmd, Ubuntu is moving to it in the future and older RH has upstart and/or int. ( And slackware think it is to complicated)
Here Red Hat RHCSA & RHCE minor changes. - CertDepot
The video course I am doing doesn't mention it at all so far. (A good intro course BTW, was great value at $25 on the Udemy sale)
(https://www.udemy.com/red-hat-certified-system-administrator-exam-ex200-rhcsa/#/ )
RH7 has sytemmd, Ubuntu is moving to it in the future and older RH has upstart and/or int. ( And slackware think it is to complicated)
Here Red Hat RHCSA & RHCE minor changes. - CertDepot
The video course I am doing doesn't mention it at all so far. (A good intro course BTW, was great value at $25 on the Udemy sale)
(https://www.udemy.com/red-hat-certified-system-administrator-exam-ex200-rhcsa/#/ )
Comments
Also any general discussion on the different systems in the real world would be welcome.
My way for learning for RHCSA/RHCEv7 exam is to do all the tasks from RHCEv6 on RHEL v7 with IPv6 and MariaDB as additional tasks.
I have to recertify my RHCE to get RHCA
These commands no longer work in Grub2's bash shell. Unfortunately I'm still trying to learn how to find the root partition in case the grub entry is messed up but at the very least you should probably learn how to boot an OS from Grub2 manually. The link below is what I learned from last night.
Load kernel and boot your system with GRUB2 - markomedia Technologies
So here is what it meant for me
Other things I've learned from Grub2
Another big thing is that changing the root password is no longer the same on RHEL 7.
RHEL 7 / CentOS 7 : Recovering / Reset Root Password @ All Linux User's Blog
The link above provides step by step instructions but I'll elaborate as well.
As you probably know by now to change the root password in RHEL 6 you would boot into runlevel 1 by either adding single or 1 to the end of the line on the bootloader starting with Linux. That will not work anymore as even if you get to run level 1 you won't be able to set the root password that way as you'll only be given the option to enter an existing root password or ctrl+D for maintenance.
In RHEL 7 you have to add init=/bin/sh instead of 1 or single.
Also the part that will absolutely kill you if you forget to take care of it is in order for the new root password to sync for when you reboot the system you must MUST MUST ABSOLUTELY HAVE TO do the following otherwise SELinux will block the new root password you set and you'll be back to square 1.
The only thing I want to learn now is how to reinstall grub from the grub2 minimal Bash shell so if anyone knows that please let me know.