Few days ago after restart ubuntu (16) won't boot again.
System asks for disk encryption password, after this step screen goes black and switches between black and dark grey, with white dash appearing sometime on top left, sometimes not.
It looks like it is trying to start but it won't go through.
I decided so to reinstall everything, but I would like to backup my home before doing so.
But the problem is: when I start in recovery mode and I drop to root shell prompt, this only lasts for a few minutes - after that it opens the recovery menu again and does not accept input from keyboard again.
This way it is not possible for me to make a proper backup before reinstalling the system (I can remount in write mode, login as user, mount the disk, start the syncing... but after few minutes it kicks me out!!!).
Any clue on how to enter a "stable and long lasting" recovery prompt?
Or what am I doing wrong?
Any help very much appreciated, thank you!