[Users] Settings lost after node reboot

Hi, Migration failed due to a lack of an iptables rules about tls I added it in /etc/sysconfig/iptables and migration worked. After a reboot, this rule is lost, as well as some setting I added in /etc. I see the the nodes have very specific mouting strategies, and/or read only architecture. I'm not sure I want to become an expert about why and how it's done, but I'd be glad if someone just tells me where I have to write my settings in order them to resist node reboot? Thank you. -- Nicolas Ecarnot