You can set it up as mnt or media for usb, as the flash drive will be located at either. If it’s set up as mnt, you have to set the pi to auto mnt a drive for you I believe, but in anycase it works nicely. I use a flash drive on some of my Pis, and a usb hdd on others, and whats nice about setting up your games in the mnt dir, is you can swap out a hdd with a flash card at any point and it will still read the games fine. If you only use media the HDDs wont show up under that from what I have seen. So you would be required to repoint ES to the roms folder under MNT… Basically if you set it up to read from mnt, both flash drives and usb hdds will be auto detected on boot and the games will load fine from either.

The easiest thing to do is simply movie your games to the usb flash drive, give it read/write permissions, and then point the emulationstation cfg to point to that new dir now for games…One thing I still do is I keep my saved games for all systems on the sd card, but store the roms for the bigger titles like PSX games on the flash drive/hdd. This seems to make things easier when it comes to saving/loading etc as sometimes its a bit hard to give the correct permissions to the flash drive/hdd to allow this to happen.

a guide for this would be good!

There are many…. One being stickyed on the top of the forum….