Thank you guys, it seems like you kicked me in to the right direction. I remade whole server to be sure, reinstalled FOG using wiki guide and as far as the startup script go, I just needed to write this:
#!/bin/bash
sleep 30
touch /var/lock/subsys/local
systemctl start mysql
exit 0
I was just dumb enough to not realize, that you need to write this script only in case, when something does not work. Well, sorry about that 🙂
Now everything seems to run fine - I don’t need to do a damn thing even after a reboot. Nice!
As to why I needed to do these timing stuff in the first place - since you all claim that CentOS is otherwise rockstable - I seriously don’t know myself. If you want to look into it, I don’t mind to cooperate with you guys.
Thank you guys!