Updatedb command by default does not include /media path for updating its database. You can change the settings in /etc/updatedb.conf so that it starts indexing other partitions too.
sudo gedit /etc/updatedb.conf |
In the PRUNEPATHS setting, remove /media. Save the file and run
sudo updatedb |
This will index all your files from /media folder. Make sure the partitions are mounted.
Cheers!