-
I don't really understand what you are trying to do
There's two parts really now:
1) simplest way to restore any one of the devices should the sd corrupt
2) where can I best learn about options for reliable home network file storage? Most likely pi based i guess as I'm down this well now.
rhb-
On 1, it might be worth deciding if you want to restore or rebuild? Is there data you need backing up, or is it just being able to set a pi up the same way if the SD card falls over?
-
1) Copying a live filesystem isn't a very good way of running a backup. You can end up with corrupt files because the OS/app had them open at the time, missing boot partitions etc. Hence I don't think it is a good idea to try and clone the running system.
2) The trouble with a Pi based thing for storage is by the time you connect a couple of drives you end up with a mess of cables and power supplies. Much easier to buy an appliance. I've got a Synology (DS420j) which just works. I have 3 drives and a RAID config (actually SHR) so if one fails I can replace one and not loose data.
-
for 2, you can also just use https://pimylifeup.com/raspberry-pi-openmediavault/ (see: https://www.openmediavault.org/ for the main software)
I run OpenMediaVault on an old PC and it works great. It can do raid like people have talked about, but I actually use UnionFS + SnapRAID to kinda do the same thing (but allow me to use drives separately if something fails)
atk
jellybaby
Kirth
I don't really understand what you are trying to do but I wouldn't try to backup a Raspberry Pi including the OS.
I'd work on your build/install process (write Raspberry Pi OS to SD card, apt-get install foo, copy config file to /etc/whatever) and then backup the config files and user data to your favourite cloud storage thing.