Ubuntu

Ubuntu is a linux distribution derived from debian. It's a very nice plug&play OS with all features I need.

cat /etc/os-release
cat /etc/lsb-release
lsb_release -a: Show the currently installed version. os-release has most information.

Modfications made

The few things I needed to tweak are listed here.

NetworkManager

NetworkManager is a bad idea, just use /etc/network/interfaces and /etc/resolv.conf to configure your network. Having a DHCP server to supply network configuration is fine, everything else is making things complex. You may need to install ifupdown and disable the netplan thing to achieve this.

Uninstall dhcpcd
Uninstall openresolv

Snap

Another bad and confusing idea is snap. E.g. Jupyter I could not get working the way I want is with the Jupyter snap. Remove it like described by techwiser. First remove all snaps, then removed snap itself and make sure it will not reappear.

snap list
snap remove --purge <package-name>
rm -rf /var/cache/snapd/
apt autoremove --purge snapd gnome-software-plugin-snap
rm -fr ~/snap
apt-mark hold snapd

Settings GUI

One day I could not start the settings GUI anymore. Removing the unity-control-center fixed the problem one time. On another install it didn't.

sudo apt-get remove unity-control-center

Display

When I connect a monitor to my laptop on HDMI automatically a 3^rd VGA display is found.

xrandr --listactivemonitors: Show all active monitors

xrandr --output VGA-1-2 --off: Turn off the VGA display. The name may differ on other configurations.

Slow boot

If /var/log/syslog is full of messages like 'failed to bind to /tmp/.X11-unix/X....', make sure / is owned by root.
Check Networking#Interfaces for allow-hotplug

Application management

apt install <package>: Install a new package
apt remove --purge <package>: Remove a package and all related files
apt update
apt full-upgrade: Update the package meta-data and update all

apt-get autoclean: Remove all obsolete package files from /var/cache/apt/archives. Do this every now and then

Add applications

To add an application to the 'Open with' list edit /usr/share/applications/<newapp>.desktop.

For opening jupyter notebooks I added jupyter.desktop that looks like below. I don't think everything is needed but it works.

[Desktop Entry]
Type=Application
Version=1.0
Name=Jupyter
GenericName=Jupyter notebook
Comment=Prototyping and documentation 
Exec=jupyter notebook %F
Icon=jupyter
Terminal=false
Categories=GTK;Development;IDE;
MimeType=text/plain;text/x-python;
StartupNotify=true
Keywords=Python;Editor;

Autostart applications

To automatically start an application when a user logs in put a link to /usr/share/applications/<newapp>.desktop or a new <newapp>.desktop in ~/.config/autostart

Problem upgrading package like 'errors were encountered while processing'

It is pretty old but some good hints can be found on journalxtra.com