In this case, I think the last option (newer RaspiOS) is the one to try out.

You can mount the usb stick once and then either link or mount its directories. For this simple purpose, links and mounts should be mere preference, although they have some differences. I prefer mounts for their heightened transparency to the system, but others prefer links.

Just search the web for either "linux symlinks" or "linux bind mount" for a ton of how-tos about them, like this one or this one.

edit: If you put the contents of roms in the root directory of the stick, you can also mount it directly onto the roms dir on your memory card. Mind that this will make anything in the card's roms dir unavailable for the duration of the mount.

@mitu Thanks a lot with that final touch works !!!
Thanks a lot for your help !
Br

@davidr said in retropie-mount automatic mount method now working properly - emulation station is missing some consoles:

Now when I boot all consoles disappear and all I see are my colections with 0 games in them. Seems like I need to keep all the roms on the sd card so whats the point of doing this in the first place.

Again, the same advice - restart ES once the startup finishes. If your ROMs show up, then you need to delay the ES startup until your drive is mounted and the USB rom folders show up.

I figured it out.

Problem was I followed a tutorial somewhere that said to make a folder called retropie whereas the official instructions state to make a folder called retropie-mount.

"retropie" will in fact copy everything to the HDD, but it will also copy from the HDD to the SD.

"retropie-mount" seems to copy everything from the SD to the HDD but will not copy everything back to the SD.

"retropie-mount" is sufficient to mount the HDD and play games. I did not need to follow all the steps to manually mount the HDD as mine is going to be portable.

@DarkkMatter the retropie system is created from the $HOME/RetroPie/retropiemenu folder - make sure you copied it to the USB along with the roms, splashscreen, BIOS folders. If in doubt, you can re-install the retropiemenu package from the RetroPie-Setup script and it will be re-created in the correct location.

@Inkdork
On your desktop, open the file explorer and then select edit
File [Edit] View Sort Go Tools
"Preferences"
"Volume Management"
Then fill out all the checkboxes under auto-mount.
I guess if they are already checked, it may be worth a try to uncheck and reboot; then recheck them and reboot.