Obsidian - Lets Talk About Backups 

I always recommend the 3,2,1 backup method. 3 copies of the data, on 2 different types of media (hard drive (internal or external), USB, dvd) , 1 copy to be offsite. I tend to use Syncthing and FreeFileSync

Perfect timing, I'm getting anxious about sync screwing things up! I've lost a bunch of calendar dates for my Call of Cthulhu campaign before and it was such a pain! Looking forward to digging into this later today.