[Ubuntu] upgrade to 16.04 fails

[conor9]

Really confusing problem, hope someone can help.

I tried upgrading from 14.04 to 16.04. (System prompted for version upgrade after recent regular software upgrade)
I let it do it. I watched it download the packages, that seemed fine.
It warned about xscreensaver and xlockmore. I killed both before proceeding
It then installed the packages and seemed to get stuck on the fonts.
Eventually it resumed, but the screen showed a message about low graphics mode.
It then gave an empty dialog with no options. I clicked OK and the system dropped to a flashing cursor.
I left it for 30mins before forcibly rebooting.

It booted into a shell, but I can't login.

This is where it gets tricky. I had the box set to auto login.
I know the password for su operations (e.g. to install software etc) - indeed, I needed it to start the upgrade. But the problem is that I can't think what the username is. I've tried my usual suspects but no joy.

I've tried to boot to recovery via GRUB, but when I select recovery, it drops to tty1 and looks for a login, without asking what I want (such as root shell etc.)

I've tried editing the grub entry to give me a root prompt (rw init=/bin/bash) but the USB keyboard doesn't work.

I've booted it from a live CD and can see the hard disk, but not sure what else to do.

Can anyone help please?

Thanks!

[Bashing-om]

conor9; Hey !

In small steps toward recovery .
Let's find the user ID.
From the liiveDVD booted in try ubuntu to a terminal ( ctl+alt+t) :


sudo parted -l # to find the root partition .
sudo mkdir /mnt/looksee/
sudo mount /dev/sda1 /mnt/looksee/ # let's "suppose" sda1 is where the root partition is, adjust as needed ##
ls -al /mnt/looksee/home/

In the output from the ls command is "your" user directory that will be named as "you"
example:


drwxr-xr-x 28 sysop sysop 4096 Mar 1 12:56 sysop

where my username is "sysop" .

Now when all done looking around. as we mounted the file system it is our responsibility to UN-mount it. Failure to UN-mount can lead to file system inconsistencies !
unmount:


sudo umount /dev/sda1 ## or whatever the actual mount point is ( sda1 ??)

Next is to see what happens attempting to boot into the install.



all in the process

[conor9]

@bashing-om:

Ahh good stuff. Didn't even think of that.
OK, I can login [ stupidest username of all time :) ]
It says welcome to Ubuntu 16.04.02 etc

I tried to get it to refresh the apt by doing apt-get update but it reported that I need to run dpkg --configure, so that's running now.

When it does finish, where to look for what went wrong?

Thanks for the help

[Bashing-om]

conor9; Hey hey !

We make progress !

As to :


where to look for what went wrong?

could have been any number of causes . My opinion without looking is the screensaver active.

We get the system stable we can go looking as you please .



we can do that

[conor9]

I'll update when dpkg is finished.

As mentioned, I did a killall of the screensaver so I'm not clear on how it would have restarted itself, but let's see.

[conor9]

Dpkg finished and rebooting, it went straight into GUI - hooray!

Any installation logs I can check to see if I can work out what happened?

[Bashing-om]

conor9l Great !

1st order of business now that you are up is to insure that the package manager is in a consistent state of mind - such that the system is happy also:


sudo apt autoclean
sudo apt autoremove
sudo apt clean
sudo apt update
sudo apt full-upgrade
sudo apt -f install
sudo dpkg --configure -a
sudo dpkg -C

if all comes back clean - dpkg returns only to prompt - then we are home free. Ya done it !

Now log files:
anything left over in " /var/log/dist-upgrade/ " ?
Have a look " /var/log/apt/term.log ", "/var/log/dpkg.log" and "/var/log/dpkg.log.1" .
These should give hints of any problems.




wiping the sweat off