If the installed hard disk becomes too small and the computer allows the installation of a 2nd disk, you can configure such 2nd disk to mount automatically during booting time. To do so you have to:
sudo pcmanfm &
(enter).
sudo blkid
, search for your 2nd drive in the list and write down its UUID.
sudo nano /etc/fstab
[Enter]
UUID=[add here the UUID of the 2nd disk you wrote down above]
/mnt/[add here the name of the 2nd disk folder you created above] auto defaults 0 0
sudo pcmanfm &
, go to your 2nd disk folder and right click on it with your mouse. Under properties, select "Access rights for others", check the "Allow create or delete new files / folders", and then "Apply to all folders".
Re-boot your computer. The new disk should be automatically mounted.