I've been trying to start a graphical session with all users on my system but I've been always reverted to the login screen.
After initiating a terminal with (Ctrl+Alt+F1) from there, I've been able to start terminal sessions with all users, so this means passwords are not the problem.
With a superuser and the terminal I've been able to check what I was suspecting:
$ df -h shows no available space on
/dev/sda1 (filesystem root) despite partition size is 64 GB and 61 GB are used. The fact is that Mint was warning me about this but I thought 2 GB free was enough to keep running the system. My mistake was clear when I tried to start up next day!
So I've been moving files from
/home to another partition and removed apt cache executing
$ (sudo) apt clean but
$ df -h keeps saying there's no available space after that. Therefore if this is the problem, how do I fix it in order to be able to start a graphical session? How much space is needed or should I reserve to prevent this happen in the future?