i was about to post a classic wux thread here. then...

[wuxmedia]

i googled around and found if one doesn't change an out-of-date partition in fstab (which can happen hopping about) all you get is a blank screen and emergency mode....
i commented out the offending out-of-date mount entry (cb in this case) and yay! back in!

just wondered where and if i should write a short note on the wiki...

and i'm happy i solved a prob without wasting your time 8)

[machinebacon]

Yes, that's systemd!

The easiest way is like this:
- wait until the emergency mode kicks in (can take a few minutes)
- enter the root password
- umount -a (ignore the error about mounted devices)
- nano /etc/fstab and set a # in front of every entry except root (/) and swap
- mount -a
- exit (Cltr-D I suppose)

The fstab will be rebuilt nicely if you use disk-manager.

[wuxmedia]

ah you fixed it anyways!!
i thought it might be a systemd thing as it mentioned systemctrl.
emergency mode took ages, when it did it was still a blank screen, i got lucky that it showed up once.
oddly on 'recovery mode' that some kind soul had thoughtfully put on the grub menu, ctlr-d just goes through...
one of those 'now you know' things.
thank you sensei

[machinebacon]

I recommend storing http://freedesktop.org/wiki/Software/systemd/Debugging in your bookmarks (on a rescue system), a must-have :)

[wuxmedia]

nice, thanks - will do.