I do use duplicati for my desktop and its great.

This is more and issue of having matching, linux, and 1 windows (soon to be linux) pc. So mixing and matching is hard. I have 1 nas for movies and music and my other nas is for music production backup. That one auto backs up from my Mac.

So then, every few months I copy that nas onto another drive and put it in the safe. I guess I want a better way to do that other than plugging the drive into the nas and manually copying everytbing over.