Disappearing files / *partial* read-only filesystem

Hi All,
I have Hass.io installed on a RPi 3B. Everything works well, including saving to SMB shared and installing add-ons. However, whenever I create a file through the SSH shell (using vi or nano), the file disappears after a reboot. I see that others have issues with a read-only filesystem, but mine isn’t read only: it can save through SMB and HA itself can write to disk just fine. But still, some updates (through the shell) aren’t lasting. Any ideas?

One important bit: this seems to be true only for items outside /config or /share (and perhaps the other SMB shared). For example, if I try to write to /root or /usr/local/bin.


Ahh… I’ve learned much in the past few days about Docker… I think it answers my question. Thx.