Restarting a hidden system

[pwabrahams]

I spent quite a few hours getting a Kubuntu system set up, and when I powered down the computer it was still working correctly. But now when I power it up again, I get the Kubuntu banner -- and then a blank screen. I don't want to go through all thework of setting that system up again, since I'm sure it's all there, just hidden. I can get a Kubuntu system running from a memory stick, and from there I can access the hard drive. Is there a way I can get my previous system back?

[VMC]

From grub boot menu, edit "e", edit out "quiet" splash" from the linux line of grub.cfg, then F10, and see what messages appear or where it hangs up.

[pwabrahams]

Well, after poking around the net for a while I actually managed to solve the problem:

1. I booted into the recovery system (a Grub choice),

2. After the gears whirred for a while, I got to a menu with, among other choices, resume.

3. (after more whirring of gears) I got to a command prompt. I logged in and immediately went into superuser mode with sudo su.

4. (This is the really nonobvious part.) I typed apt-get install xorg.

5. (More whirring of gears) I typed reboot.

6. My system came back to life!!!

Perhaps the Sages of Ubuntu will be able to provide an explanation of all this. Meanwhile, I think this is a recipe that works for the nonexperts.

[cruzer001]

nomodeset?

https://ubuntuforums.org/showthread.php?t=1613132

Not familiar with KDE so just some guesswork on my part.

[again?]

Well, after poking around the net for a while I actually managed to solve the problem:
4. (This is the really nonobvious part.) I typed apt-get install xorg.


Perhaps the Sages of Ubuntu will be able to provide an explanation of all this. Meanwhile, I think this is a recipe that works for the nonexperts.
xorg is a default install metapackage (https://help.ubuntu.com/community/MetaPackages), which means it's just a list of dependencies.
If you remove one of those dependencies it will remove the xorg metapackage as well.

If I try to install xorg...

glen@Bionic:~$ sudo apt install xorg
[sudo] password for glen:
Reading package lists... Done
Building dependency tree
Reading state information... Done
xorg is already the newest version (1:7.7+19ubuntu7.1).
0 to upgrade, 0 to newly install, 0 to remove and 0 not to upgrade.

Maybe somewhere in your customizing you removed an xorg dependency needed for a graphical boot.
Show xorg dependencies...

glen@Bionic:~$ apt show xorg
Package: xorg
Version: 1:7.7+19ubuntu7.1
Priority: optional
Section: x11
Origin: Ubuntu
Maintainer: Ubuntu X-SWAT <ubuntu-x@lists.ubuntu.com>
Original-Maintainer: Debian X Strike Force <debian-x@lists.debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 57.3 kB
Provides: x-window-system, x-window-system-core
Depends: xserver-xorg (>= 1:7.7+19ubuntu7.1), libgl1-mesa-glx | libgl1, libgl1-mesa-dri, libglu1-mesa, xfonts-base (>= 1:1.0.0-1), x11-apps, x11-session-utils, x11-utils, x11-xkb-utils, x11-xserver-utils, xauth, xinit, xfonts-utils, xkb-data, xorg-docs-core, gnome-terminal | xterm | x-terminal-emulator, xinput
Recommends: xfonts-scalable (>= 1:1.0.0-1)
Suggests: xorg-docs, xfonts-100dpi (>= 1:1.0.0-1), xfonts-75dpi (>= 1:1.0.0-1), x11-xfs-utils
Homepage: http://www.x.org/
Task: ubuntu-desktop, kubuntu-desktop, xubuntu-core, xubuntu-desktop, ubuntustudio-desktop-core, ubuntustudio-desktop, ubuntukylin-desktop, ubuntu-mate-core, ubuntu-mate-desktop, ubuntu-budgie-desktop
Supported: 5y
Download-Size: 3,076 B
APT-Manual-Installed: yes
APT-Sources: http://ftp.iinet.net.au/pub/ubuntu bionic-updates/main amd64 Packages
Description: X.Org X Window System
This metapackage provides the components for a standalone workstation
running the X Window System. It provides the X libraries, an X server, a
set of fonts, and a group of basic X clients and utilities.
.
Higher level metapackages, such as those for desktop environments, can
depend on this package and simplify their dependencies.
.
It should be noted that a package providing x-window-manager should also
be installed to ensure a comfortable X experience.

N: There is 1 additional record. Please use the '-a' switch to see it

Search your apt history in /var/log/apt/history.log for "xorg" and see what was installed at the same time.

Or maybe you just encountered a bug???

[pwabrahams]

Even as a nonexpert, xorg seemed to me to be something that should have been there. The fact that bootup died after displaying the Kubuntu banner was proof positive that something was wrong. So given this particular misbehavior and the fact that I was working with a crippled system in trying to deal with it, what would have been a wiser way to go about it?

[again?]

I am not saying you did anything unwise attempting to fix your system...
just tying to help you find out how you got there.
Did you check in /var/log/apt/history.log what packages were pulled in when you reinstalled xorg?