I think you might be confusing a few things.
It depends on how you set up your partitions, it sounds like you assigned 10gigaybtes to the root partition.
If so, you can change your image store location to say /home/fog/images instead.
sudo cp -Rf /images/* /home/fog/images/
Then
sudo chown -R fog /images
sudo chmod -R 755 /images
sudo chmod -R 777 /images/dev
Then edit /opt/fog/.fogsettings and change storageLocation to /home/fog/images
Rerun the installer and it should fix everything else. If not, check /etc/fstab and Storage node location.