I ran an update from Ubuntu 16.04 and cannot boot anymore. I took all the distribution options when there was customized config conflict. I didn't do anything fancy during the update process otherwise.
Screenshot: https://drive.google.com/open?id=1XsRTLKEkgMivxd0aSezYyt9EBq89_qKQ
That one is when I tried to use 4.4.0 in safe mode. The other option is 4.15.0, but the result is the same. Basically, I cannot get any further beyond grub.
How can I get out of this?
Ok, this was a self-inflicted wound. As I mentioned, I moved /usr to /home and linked /usr to it in order to free up space for the upgrade. Looks like during the upgrade the link (while still pointing to /home/usr) got invalid somehow.
When I was in the live Linux, I copied usr back. Luckily there was still enough space. After that all the boot problems disappeared. Lesson: don't mess with system files. On the bright side - it did enable me to upgrade the OS, and I now have a bootable Linux USB as a bonus :)
In many cases this will be due to the /boot drive becoming 100% full because many updates have been made to the kernel. By default, ubuntu will retain the old kernels and add them to the list of available kernels you can boot into in the Grub2 boot loader menu.
Restart OS. Into the Grub2 menu then choose Advanced options for ubuntu view where you can see a list of old kernels you can boot into. Some report you can do this booting with the Shift key held down.
Choose the next-oldest kernel from the top/highest version of kernels. Try found kernel to login.
Then run:
uname -a
Note kernel version. Run:
dpkg --list | grep linux-image
Find all the kernels that are lower than your current kernel version. Run the commands below to remove the kernel you selected:
sudo apt-get purge linux-image-x.x.x.x-generic
update grub2:
sudo update-grub2
Reboot system.
Helping sources:
