There isn't a good way to back up lightning network nodes.

When hardware fails the best you can hope for is your channel partners cooperatively close your channels with them.

I suppose watchtowers can make sure they're fair too, but you cannot initiate the close or reopen the channel because broadcasting old channel state gets your funds taken.

So by not allowing a 2nd server to run or some way to keep live backups lightning network has a hole in it's robustness.