What is an alternative to OPENSUSE /etc/config.sys/ on LINUX MINT or UBUNTU?
Do you mean /etc/sysconfig? Because according to the documentation, /etc/sysconfig is sort of a catch-all system configuration location that's unique to SuSE. Kind of like how /etc/rc.conf is (sort of) unique to Arch. Ubuntu's system configuration is spread across many files and directories in /etc. Really though, if there is something that you want to tweak that you're unsure about, I guarantee you're not the first person to do it--community documentation is your friend.