Running roms off a USB

AndersHP

OK, to answer my own questions, if the USB drive is inserted into the Pi, it's read before the RetroPie folder that still exist on the SD card (even figures like normal in the File Manager), and if the USB drive is not inserted, the system looks at the SD card instead.

So what I'm doing now, is after the automount method has copied everything onto the USB, I unplug the USB drive and remove all my ROMs from the File Manager (as this will make the File Manager look at the content of the SD). After that, I can be sure that there's no ROMS on the SD, and everything is running off the USB.

Dominus

I'd just open your network \\retropie go to Roms, and delete or cut the folder you want to move to USB. Then go to home/retropie/roms/ and then type sudo ln -s /media/usb0/XXX XXX (XXX for whatever system you want to be used on the USB instead. That's it. It should automount or whatever and load every time! If you want to move all your roms to a USB, do the same thing, but WinSCP into the Pi, go to your Roms directory and delete or cut all of it as before, and then go to home/retropie (in Putty or Commandline btw), and type sudo ln -s /media/usb0/roms roms

skeeto1983

I have a question concerning the auto-mount feature and using a USB as a ROM/save state backup. Using the Github guide, I performed the auto USB transfer. It all functioned as designed to setup the USB. I understand that now I will be playing and saving the ROM data to the USB.

My question is if an issue should occur with the SD in the future and I need to restore the retropie image, if I repeat the process as directed, wont RetroPie just perform the copy again with virgin roms and copy over all my USB roms with save states? I'm not exactly sure how this is intended to work.

The only way around this that I can see is to perform a backup of the SD .img file AFTER the transfer to USB has taken place. That way, if you need to restore the image from the backup, the link to the USB drive is already there and it will function as it did previously.

Also, once the transfer to USB is complete with all the ROM data, is there a need to DIS-able the auto-USB transfer function in the retroarch setup menu before I perform the proposed IMG backup as above.

Again, I'm just taking a shot in the dark here with how I assume this might work, I'm all ears for a little assistance.

Thanks in advance
Rob

lostless

@skeeto1983 the way it works now is so much easier in 4.2. All you have to do is make folder called retropie-mount on the root directory of the usb stick and put the rom folder in there. Retro pie will auto mount the folder and use USB stick for all roms and saves. Nothing will copy over to the pi's internal sd card. No ned to relink anything. So if you do reimage the sd card with a fresh install, all your rom will be immediately available from the USB stick. The only thing is all configs and game art will still be handled by the internal sd.
If you remove the USB stick and reboot, retropie will switch back to the internal roms folder.

skeeto1983

@lostless,

Thanks for clarifying. The current backup SD image I have is from prior to setting up the USB auto transfer and telling RetroPie to "look" for the USB for save-states and playing the ROMs. My only concern is that if I ever restore from that image and try to play as normal, it will ignore the USB as it predates that setup and will just use all the ROMs on the SD card. Worse, I afraid that if I try to re-link a new image to the USB, it will overwrite the USB folders in retropie-mount with the fresh ROMs from the SD and I'd lose all my saves, etc.

Does this make sense or am I making a big deal over nothing?

Galahad1980

@lostless Hello Lostless, you seem to be quite knowledgable on the subject. I was just wondering when transferring roms to USB stick, whether the OS is also copied and therefore the SD card does not have to be present on boot up, or is it just the rom directories that are copied across.

Galahad1980

@Galahad1980 Please ignore, I have just seen Dankcushions has already answered this question.

skeeto1983

@lostless,

Ok so I think I understand the process here involving the USB ROM directory. In the event of a new SD image, once I enable the transfer service in the config menu, the Pi will look to the USB and WON'T mess with any existing files. The .state and .srm files in the USB drive will remain untouched since they won't have existed on the original SD image that I am restoring from.

Let me know if I have that right.

Al2017

@lostless I am using a USB drive for my psx roms. Is there any reason some roms don't work? The same rom files work when installed on the SD card, just not when they are on the USB drive.

lostless

@Al2017 you also have to copy the bios file to the USB drive.