I’m duplicating my server hardware and moving the second set off site. I want to keep the data live since the whole system will be load balanced with my on site system. I’ve contemplated tools like syncthing to make a 1 to 1 copy of the data to NAS B but i know there has to be a better way. What have you used successfully?
If you want to mirror the entire system, OS and all, then clonezilla is the best option.
That won’t keep it constantly in sync though