Debian Post Install

Enable contrib and non-free sources

Using the terminal, edit the following file, add the “contrib” and “non-free” sources, or replace with these lines:

sudo vim /etc/apt/sources.list

deb http://deb.debian.org/debian bookworm main contrib non-free non-free-firmware
deb-src http://deb.debian.org/debian bookworm main contrib non-free non-free-firmware

deb http://deb.debian.org/debian-security/ bookworm-security main contrib non-free non-free-firmware
deb-src http://deb.debian.org/debian-security/ bookworm-security main contrib non-free non-free-firmware

deb http://deb.debian.org/debian bookworm-updates main contrib non-free non-free-firmware
deb-src http://deb.debian.org/debian bookworm-updates main contrib non-free non-free-firmware

Enable bookworm backports

Again, using the terminal, edit the file /etc/apt/sources.list and add the following lines:

# bookworm-backports
deb http://deb.debian.org/debian bookworm-backports main contrib non-free
deb-src http://deb.debian.org/debian bookworm-backports main contrib non-free

Update the package manager
```
sudo apt update
```

Enable 32bit packages

sudo dpkg --add-architecture i386 && sudo apt update

Enable Flatpak support

sudo apt install flatpak

sudo flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

sudo apt install gnome-software-plugin-flatpak

Install and configure Virtual Manager

sudo apt install qemu-system libvirt-daemon-system virt-manager

Using vim (or any other text editor), open libvirtd.conf and enable these two lines:

sudo vim /etc/libvirt/libvirtd.conf

unix_sock_group = "libvirt"
unix_sock_rw_perms = "0770"

Start and enable the libvirtd service:

sudo systemctl enable libvirtd && sudo systemctl start libvirtd

Add your user to the libvirt group by typing this command:

sudo usermod -a -G libvirt $(whoami)

Start the default network and enable autostart:

sudo virsh net-start default && sudo virsh net-autostart --network default

Fix slow shutdown

Edit system.conf and change the default value from 90s to 15s (or 10s):
```
sudo vim /etc/systemd/system.conf
```
```
DefaultTimeoutStopSec=15s
```

Remove all pre-installed GNOME games

Run:

sudo apt purge iagno lightsoff four-in-a-row gnome-robots pegsolitaire gnome-2048 hitori gnome-klotski gnome-mines gnome-mahjongg gnome-sudoku quadrapassel swell-foop gnome-tetravex gnome-taquin aisleriot gnome-chess five-or-more gnome-nibbles tali
sudo apt autoremove

Or just run:

sudo apt purge gnome-games

Fix broken QT application theme

Follow the steps covered under the GNOME documentation.
Font configuration guides

There are two guides that I’ve created; I highly recommend going through them to improve font rendering on Linux.

Click here to go direct to the guide 1

Click here to go direct to the guide 2
Set up firewall

Follow the steps here