Running roms off a USB

iconrumble · 8 Sept 2016, 07:55

@Juakin In my case, I swapped the psx folder on the sd card with a symlink, so I can only see isos on the usb. You could create the symlink inside the sd psx folder (just like a subfolder), that way you can put isos in the sd card and the usb.

@Dominus @Juakin My 64gb fat32 usb get's automounted at boot, I didn't have to edit the fstab or do anything else. I'm running of retropie 3.8 image updated to 4.0.1

Juakin · 8 Sept 2016, 11:31

@iconrumble said in Running roms off a USB:

@Juakin In my case, I swapped the psx folder on the sd card with a symlink, so I can only see isos on the usb. You could create the symlink inside the sd psx folder (just like a subfolder), that way you can put isos in the sd card and the usb.

That's exactly what I did, now I can load my ISOS from both places.
Thanks for the info.

AndersHP · 27 Oct 2016, 06:46

Wow, having just read this topic I'm getting convinced that even I can do this.

Does this generally slow down or in other ways stress the Retropie? And what are the exact benefits of running ROMs off a USB, if there's Space enough on the SD?

Apart from that, do you just use USB Sticks, or USB external harddives? Are there any min. requirements for the USB (read/write speed etc)?

What about Steven Selph's scraper. will this also understand the symlink and still scrape the games?

dankcushions · 27 Oct 2016, 09:12

@AndersHP said in Running roms off a USB:

Wow, having just read this topic I'm getting convinced that even I can do this.

Does this generally slow down or in other ways stress the Retropie?

no. USB transfer will probably be faster than SD cards (?), but in any case it doesn't really matter.

And what are the exact benefits of running ROMs off a USB, if there's Space enough on the SD?

the benefits are listed here: https://github.com/RetroPie/RetroPie-Setup/wiki/Running-ROMs-from-a-USB-drive

Apart from that, do you just use USB Sticks, or USB external harddives?

i use a USB stick. a harddrive seems excessive. that amount of ROMs would surely grind ES to a hault.

Are there any min. requirements for the USB (read/write speed etc)?

no.

What about Steven Selph's scraper. will this also understand the symlink and still scrape the games?

i don't use symlinks, i use the recommended mount method. i would have thought it would, though.

spannernick1 · 27 Oct 2016, 12:37

Edited... question already be asked.

Dominus · 27 Oct 2016, 22:10

@AndersHP @dankcushions
I find that save states take a hell of a long time to save! I have PSX and GBA on my USB stick, and I bet it takes 10 seconds or more to save PSX games (loading is pretty instant it seems), and GBA about 5 seconds? Just looking into why that is (could be my USB stick?) or to move the save states to the SD card.

dankcushions · 27 Oct 2016, 23:24

@Dominus said in Running roms off a USB:

@AndersHP @dankcushions
I find that save states take a hell of a long time to save! I have PSX and GBA on my USB stick, and I bet it takes 10 seconds or more to save PSX games (loading is pretty instant it seems), and GBA about 5 seconds? Just looking into why that is (could be my USB stick?) or to move the save states to the SD card.

it may just be the emulation. the original psx memory cards were slow, so the games / bios may have no idea they are being run on much better hardware. it's the same reason load times still exist for psx games, despite running on machines that could hold the whole ISO in memory.

Dominus · 28 Oct 2016, 01:11

@dankcushions I don't know, maybe. But I'm talking about the RetroArch save states not just the regular memory card save points, as those actually work faster lol... plus I have similar issues, though not as long, with the GBA on USB.

Dominus · 28 Oct 2016, 03:34

I just timed it and it took around 23 seconds to save state on PSX, and with GBA it took around 2.5 seconds. I tried 2 different USB sticks so it's not the USB. I don't have mine mounted, would that make a difference?

AndersHP · 21 Dec 2016, 20:46

Reading the guide on Github, it seems that you have to move the entire RetroPie folder onto the USB.

Does this mean that the SD card in general is not really used anymore? I thought that it was only for running games off the USB drive. But what is exactly getting moved onto the USB? Just to get a better understanding...

Also, the guide says both "copy" and "moving" the above mentioned, but the command states 'mv'... Will some files be present on both SD card and USB drive?

dankcushions · 21 Dec 2016, 21:03

@AndersHP said in Running roms off a USB:

Reading the guide on Github, it seems that you have to move the entire RetroPie folder onto the USB.

Does this mean that the SD card in general is not really used anymore? I thought that it was only for running games off the USB drive. But what is exactly getting moved onto the USB? Just to get a better understanding...

The retropie folder only contains the roms and bios files. The operating system, setup-script, configs, emulators, etc, are still on the SD.

Also, the guide says both "copy" and "moving" the above mentioned, but the command states 'mv'... Will some files be present on both SD card and USB drive?

yeah that's a mistake - good spot! it moves the folder, not copy. there's no point having it on the SD if it's on the USB.

AndersHP · 24 Jan 2017, 18:52

So, I just realized that since december, the Github guide has changed, with an auto mount option now available.

I'm about to try this now #fingerscrossed
What I don't understand is, still, the ROMS and Retropie folder seems to get copied, not moved..?

And if the USB ROM transfer service is set to ON (as the guide tells), and I start copying games to my new ROMs dedicated USB, won't the system start copying everything onto the SD card?

AndersHP · 24 Jan 2017, 19:52

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 · 24 Jan 2017, 20:29

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 · 22 Mar 2017, 03:53

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 · 22 Mar 2017, 06:22

@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 · 22 Mar 2017, 14:57

@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 · 24 Mar 2017, 10:55

@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 · 24 Mar 2017, 10:57

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

skeeto1983 · 24 Mar 2017, 22:14

@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.