Changing default photo directory of Photo Station in Synology

to mount the folder use the following command:
mount -o bind /volume2/ePhoto2T /volume1/photo

After you have checked and tested, you can add this to the startup. Type:
vi /etc/rc.local
(My rc.local didn't exist, but vi creates it anyway)

Press a to edit and add the same line again (a on mac)
mount -o bind /volume2/ePhoto2T /volume1/photo