Setting up retropie folders on mounted hard drive

[RedDog]

Using this guide, I was able to set up an external hard drive to automatically mount when the Pi3 boots up. I mounted it to /mnt/usbstorage.

Now I am trying to find out the proper way to set up rom and image folders on the hard drive and configure EmulationStation as well as what files to edit and how. I found some posts on the forum on how to not do it, but I wasn't able to figure out the right way to do it.

I plan to store all roms and snapshots on the hard drive. I wanted to set it up this way so that if the SD card ever corrupts, it will be a relatively easy setup again (I do plan to make SD card images along the way). If someone does have a better suggestion on planning this, I also would not mind hearing it.

I am still new to retropie and linux, but thanks to setting up root access via filezilla and tinkering a bit, I am starting to find my way around the file structure.

Thanks for any help.

[dankcushions]

@RedDog check out https://github.com/RetroPie/RetroPie-Setup/wiki/Running-ROMs-from-a-USB-drive#manual-mount

if you use a combination of your guide and this one it should work. specifically, you want to mount it to the /home/pi/RetroPie folder

[RedDog]

Thanks for the advice and the second guide. I will give it a go.

[RedDog]

Thanks again. Success so far.

I redid the mounting for the external hard drive and now have it mounted to the Retropie folder and it appears to work correctly. If I have the drive plugged in on boot, the emulators show up and games work. If I boot without the drive, only the Retropie menu comes up.

I did have to manually set up the BIOS, retropiemenu, roms, and splashscreens folders and subfolders up in the root of the hard drive through Windows. I assume that is normal in this case (and hopefully I did't miss anything).

I have a few more folder questions:

1. Is the BIOS folder set up in the same way as the rom folder in that there are subfolders for each emulator (such as psp, psx, sega32x) or do you just toss all the bios files in that folder?
2. I see that the images by default are located in /opt/retropie/configs/all/emulationstation/downloaded_images. Any suggestions on what to look at to store the images on the hard drive instead? Using Sselphs scraper perhaps?

Also, what triggers retropie to generate a new gamelist.xml? Is it when the scraper is run?