@jacksmirk It seems recalbox overwrites my symlink on reboot.

What I think @eddywebs is trying to do is increase the space of /recalbox/share. I have achieved this doing the following:

• Create a dir where there is empty space, in my case I had 20GB of free space on / so I created /opt/recalbox/roms/megadrive path.
• Create a symlink to this new created directory. In my case I deleted the directory /recalbox/share/roms/megadrive and executed this line:

ln -s /opt/recalbox/roms/megadrive/ /recalbox/share/roms/megadrive

Now if you do an ls -alrth of /recalbox/share/roms you'll obtain this:

drwxr-xr-x    8 root     root         440 Feb  5 16:21 nes
drwxr-xr-x    4 root     root         180 Feb  5 16:21 mastersystem
drwxr-xr-x    2 root     root         260 Feb  5 16:21 gba
lrwxrwxrwx    1 root     root          29 Feb  5 18:36 megadrive -> /opt/recalbox/roms/megadrive/
drwxr-xr-x   45 root     root         920 Feb  5 18:36 .

Hope it helps.