OS Overview - Ubuntu Login Loop (Case & Solution)
Tags: ubuntu, linux, anydesk, teamviewer
Published: 2021-02-06 03:22:58

# Motivation
OS is just Kernel and Shell which work hand in hand. The distribution (distro) is a combination of a customized shell(s) working on a kernel. This means, for example, Kali, Ubuntu, Fedora, Mint, etc are different distros that work on Linux kernel. The shell acts as an interface between the user and the kernel.

### GNU (Gnu is Not Unix)
GNU is an Operative System. You can use this operative system with a different kernel such as Linux kernel, Hurd kernel, Darwin kernel, etc.

### Windowing System
The windowing system is just the basic layer for a GUI environment. Every Linux distribution is a GNU operative system with a Linux kernel and a windowing system (X Window System is common on Unix like systems).

### Window manager
A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment (An X window manager is a window manager that runs on top of the X Window System)

> In the case of X or Wayland Window System, the shell consists of an `X window manager` or a `Wayland compositor`, respectively, as well as of one or multiple programs providing the functionality to start installed applications, to manage open windows and virtual desktops, and often to support a widget engine.

### Linux Display Manager
GNOME Display Manager (`GDM`) is a display manager (a graphical login manager) for the X11 windowing system that lets you easily use your system. The X protocol has been at version 11 (hence "X11") 

Ubuntu GDM uses the gdm3, which is the default GNOME 3.x desktop environment greeter in Ubuntu 17.

### Wayland
Wayland is intended as a simpler replacement for X, easier to develop and maintain
![login](https://i.imgur.com/tcF98Be.png)



### Remote Desktop Control
Wayland sessions are not supported as incoming remote control connections such in AnyDesk and TeamViewer.
![login](https://i.imgur.com/n4oukki.jpg)

You could change it to Xorg on your login screen if you use Fedora
![login](https://i.imgur.com/IqH0Qda.png)

### Login Loop
However, there are still a few pain points that simply couldn't be overcome for `Ubuntu 20.04.2 LTS (Focal Fossa)` (certain video card manufacturers stand out). Migrating everybody to Wayland in the 20.04 cycle would cause too many folks' systems to break.

If you face a login loop after changing `Ubuntu with Wayland` to `Ubuntu`, one of the solutions is to change the default display manager from `gdm3` to `lightdm` through the following steps:

```bash
naser@cairo:~/$ sudo apt-get install lightdm -y
```
![lightdm](https://i.imgur.com/EjvSajd.png)

```bash
naser@cairo:~/$ sudo reboot
```
After rebooting you will notice the change in the interface
![interface](https://i.imgur.com/zKE0TcR.jpg)

Click the white cirlce and chose Ubuntu (Default)
![default](https://i.imgur.com/UbHkYSe.jpg)

You will see the windowing system have been changed from Wayland to X11
![X11](https://i.imgur.com/IG89nkC.png)

> Note: You may find that Screen lock disabled on the Ubuntu +20 flavors 

#### Resoureces
- https://wayland.freedesktop.org/releases.html
- https://community.teamviewer.com/English/discussion/1103/linux-disable-wayland-support

- https://askubuntu.com/questions/1131921/anydesk-remote-server-display-not-supported-e-g-wayland

- https://community.teamviewer.com/English/discussion/1103/linux-disable-wayland-support

- http://stackoverflow.com

## Hope this random walk adds to you.
> Incredible resources on the internet though, so be sure to share what you can't live without in the comments.

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