Storing config files on USB?

[ancapgamer]

Is there any way that I can store my custom configuration files on my pi's USB Hard drive, instead of within the standard /opt/ folder on the SD card?

I have a lot of custom settings that I've built into my RetroPie over the years - things like manually setting vertical scanlines for all the vertical arcade shooter games, manually editing bezels from the bezel project to match my ROM names so they will consistently show up, building a couple dozen custom collections for major franchises (so you can browse all the Final Fantasy, Sonic, or Mario games in one place), etc.

I also have friends and family who I regularly build or update these things for as birthday/Christmas presents, so I'm really wanting to streamline the process of setting it up as much as I can - right now everything that CAN go on my pi's attached hard drive is stored there - games, save data (separate folder from games), gamelist files, and all the scraped metadata - but I still have to store all of my per-game manual overrides (emulator choices, shaders, bezel files, etc) on the SD card, which adds another step to the process. I have this dream of being able to just flash a fresh install of RetroPie to an SD Card, copy my hard drive files over to a new hard drive, plug them both in and be done.

[mitu]

What's stopping you from backing up the config folder and restore it then restoring it on a new system ? It's available via file shares so it can easily be copied from a system to another.
You can configure your /opt/retropie/configs folder to be mounted from an external disc, but there's no automated method to do that and it might need to be a Linux (i.e. ext4) partition (because of symlink usage) - so not so easily accessible from a non-Linux PC.

[ancapgamer]

@mitu Nothing's stopping me from doing that, in fact that's my current approach - I'm just checking to see if it's possible to further optimize my setup.

[Lolonois]

Looks like a good use case for git on LAN? You can tag or branch your config sets rolled out for other machines than yours. Later merge all your latest and greatest changes from your machine into the friends' branches from time to time. If something breaks you can easily go back in time.