Default Efs ?

I can't find any info on whether or not it's imperative , or possible to back up efs on this device. I typically always back them up when I am rooted bc it's my biggest fear in somehow getting corrupted or lost, and not having anyway to restore. There doesn't seem to be a topic anywhere on These boards (DNA) so I'm thinking it's either impossible to lose or very easy to restore lol. Anyone know for Sure ?