I don’t know if EVERYONE would want this, so maybe make it an option during setup. It would be great if there was an option to have all save files for all emulators dumped into a single “saves” directory for easy backup.
I have my ROMs stored on my (gentoo-based) file server. I copied them locally to the Pi during setup. Because of this, I don’t really need to back up my whole ROMs directory on the Pi when I want to wipe the storage. What I ended up doing, is creating a “saves” directory in /home/pi/RetroPie, sticking my save files in there, and sharing it out with Samba (just append this to /etc/samba/smb.conf)
comment = saves
path = /home/pi/RetroPie/saves
writeable = yes
guest ok = yes
create mask = 0644
directory mask = 0755
force user = pi
Then bounce the service/reboot
sudo service samba restart
Once that’s set up, you can edit /opt/retropie/configs/all/retroach.cfg and uncomment/complete the save file directory line.
savefile_directory = /home/pi/RetroPie/saves
Unfortunately, this only works for Retroarch-based emulators, and others like mupen64 are still independent, so it will only be possible if the emulator supports redirecting save files.
e.g., mupen64 in /opt/retropie/configs/n64/mupen64plus.cfg
SaveSRAMPath = "/home/pi/RetroPie/saves"
The GBA emulator, for example, does not have an option like this as of RetroPie 2.6