h1 Simple, modern and secure installation of Arch Linux with KDE Plasma.

# _Load the preferred keyboard. In my case it's "de" for Germany._
$ loadkeys de

# _List devices to make sure you partition the right device._
$ lsblk

# _Partition the device using gdisk (assuming /dev/sda)._
$ gdisk /dev/sda

# _Create GPT and EFI-partion._
$ o     # _Creates new GPT-partition table._
$ y     # _Accept._
$ n     # _New partition._
$ +512M # _512 MB should be plenty for /boot._
$ ef00  # _Mark as EFI._
$ n     # _New main partition, accept all the following using "y"._

# _Print and check your partitions._
$ p

# _Write partitions to device._
$ w
$ y     # _Accept._

# _Encrypt primary partition._
$ cryptsetup -c aes-xts-plain -y -s 512 luksFormat /dev/sda2
$ YES

# _Open encrypted partition, map as "root" and create filesystem._
$ cryptseup luksOpen /dev/sda2 root
$ mkfs.fat -F 32 -n UEFI /dev/sda1
# _-F specifies the type of file allocation tables used (12, 16 or 32 bit)._
# _-n sets the volume name (label) of the filesystem to "UEFI"._

# _Create ext4 filesystem on primary partition._
$ mkfs.ext4 /dev/mapper/root

# _Create mountpoints and mount partitions._
$ mount /dev/mapper/root /mnt
$ mkdir /mnt/boot
$ mount /dev/sda1 /mnt/boot

# _Optionally update mirrorlist using reflector._
# _In this case use the latest 10 mirrors from Germany, that have been synchronized within the last 24 hours and_
# _sort the by download-rate and write them to the pacman mirrorlist._ 
$  reflector --verbose --latest 10 --country Germany --age 24 --sort rate --save /etc/pacman.d/mirrorlist

# _Install base system and basic packages (network, editor, sudo)._
# _The package base-devel is not necessary but recommended._
$ pacstrap /mnt base base-devel linux linux-firmware networkmanager nano sudo

# _Generate fstab._
$ genfstab -Lp /mnt > /mnt/etc/fstab
# _-L = Use labels for source identifiers (shortcut for -t LABEL)._
# _-p Exclude pseudofs mounts (default behavior)._

# _Chroot into your installation._
$ arch-chroot /mnt

# _Set your hostname._
$ echo mycomputer > /etc/hostname

# _Generate locale.gen for your preferred language (and preferribly english)._
$ nano /etc/locale.gen
# _Uncomment your language, e.g. de_DE.UTF-8 UTF-8 (and en_US.UTF-8)._

# _Generate the locale._
$ locale-gen

# Add necessary HOOKS and MODULES.
$ nano /etc/mkinitcpio.conf

# MODULES=(ext4)
# HOOKS=(base udev autodetect modconf block keyboard keymap encrypt filesystems fsck shutdown)

# Create mkinitcpio.
$ mkinitcpio -p linux

# Start NetworkManager for automatic network access on next boot.
$ systemctl enable NetworkManager

# Set a root-password.
$ passwd

# Install systemd-boot bootloader.
$ bootctl install

# Create the bootloader config.
$ nano /bootloader/entries/arch.conf

# Add the following:
# title    Arch Linux
# linux    /vmlinuz-linux
# initrd   /initramfs-linux.img
# options  cryptdevice=/dev/sda2:root root=/dev/mapper/root rw lang=de init=/usr/lib/systemd/systemd locale=de_DE.UTF-8

# Create a fallback config.
$ cp /boot/loader/entries/arch.conf /boot/loader/entries/arch-fallback.conf

# Edit the fallback config.
$ nano /boot/loader/entries/arch-fallback.conf

# Change it to the following:
# title    Arch Linux Fallback
# initrd   /initramfs-linux-fallback.img

# Edit loader config.
$ nano /boot/loader/loader.conf

Change it to the following:
# timeout 1
# default arch.conf

# Exit and reboot
$ exit
$ umount /mnt/boot
$ reboot

# Enter encryption-password and login as root.

# Set the keyboard to your preferred language permantently.
$ echo KEYMAP=de-latin1-nodeadkeys > /etc/vconsole.conf

# Create a user with a /home-directory.
$ useradd -m myusername

# Set password for your user.
$ passwd myusername

# Add myusername to group wheel for sudo access.
$ gpasswd -a myusername wheel

# Edit sudoers-file for sudo access.
$ nano /etc/sudoers

# Uncomment „%wheel ALL=(ALL) ALL“

# Logout as root.
$ exit

# Login as you user.

# Install SDDM and a minimal KDE Plasma.
$ pacman -S sddm sddm-kcm plasma-desktop

# Install KDE terminal for easier installation of packages in Plasma.
$ pacman -S konsole

# Enable and start SDDM to login to Plasma.
$ systemctl enable sddm
$ systemctl start sddm

# Now you are logged in to your Plasma desktop environment and ready to configure and use your Arch Linux.

# Suggested packages to install.

# microcode (https://wiki.archlinux.org/index.php/Microcode)
# kde-gtk-config (Adds graphical settings for GTK apps.)
# kdeplasma-addons („All kind of addons to improve your Plasma experience.“)
# kscreen (Adds screen section to graphical settings.)
# ksystemlog (Graphical system log viewer)
# partitionmanager (Graphical partition manager)
# plasma-nm (Network manager applet)
# plasma-pa (Audio manager applet)
# powerdevil (Adds energy manager to graphical settings.)
# spectacle (Graphical screenshot tool.)
# systemd-swap (https://wiki.archlinux.org/index.php/swap#systemd-swap)