[Borgbackup] Lots of files that change rarely and predictably

[Thomas Levine]

Thank you for the tip on lzma levels.

Putting the cache and repository on the SD card would probably make
things slow too. But if nothing in the checkout has changed, I think
the most significant part would still be the scan of the files in my
checkout, as the most of the filesystem access would happen there.

Slow storage paradigms are sometimes worth it, as I mentioned with MH.
SD card in a Raspberry Pi is the best approach I have come up with for
a disposable computer. (I say Raspberry Pi because it is the easiest one
to source in most countries; most of the competition is better if you
don't need to be able to rebuild quickly after unexpectedly throwing
your computer away.)