i abandoned dvds to keep backups some time ago, especially when i discovered that only my family pictures can fill 3 dvds and that is less than half of my personal files
i also abandoned k3b, it is not what it used to be anymore
i normally use a usb external disk or a usb flash drive, also a extra hard disk inside the machine that is never formated and when i reinstall, i unplug to avoid sad accidents
i just copy what i know it is important and the rest like basic configurations and themes, i can download or reconfigure in less than one hour