- Read careful the guide about how to restore your dead node
- To have a copy of your drive, in case of failure:
a. Use a hardware RAID with 2 or 3 disks, that data is written on all of them in the same time with parity control.
b. Make a clone, disk to disk (best to use is Acronis disk clone imager), but you will need to shut down your node, connect those 2 disks in another PC, do the cloning (will take time) and put it back. The time was offline, it will have to resync latest blocks. You will have to keep also an updated copy of your wallet.db and channel.db, taken offline. Otherwise all your copies are worthless.
So as you can see, is not easy and in special with a RPi will never be achievable. You will need a good strong barebone/PC for this.
For a RPi node I strongly suggest to have a UPS battery that will keep it alive as much is possible.