RetroPie: how to use an external HDD/SSD for your ROMs
Today I received an external SSD 128 GB (you can buy one at Amazon) for storing my ROM files, especially for PlayStation One’s ROMs because of their large size.
I added this line in /etc/fstab file to mount it automatically. In case you have an external storage with format FAT32/NTFS it will be mounted with the correct permissions rather than 777.
After adding that line, remove the /home/pi/RetroPie/roms directory and create it again but empty.
(You can get the case in the picture and other useful stuff like a micro USB with ON/OFF switch at Amazon. I separated the SSD from the RSPi case with four rubber feet adhesive.)