Arch Linux Installation Guide (UEFI) - Cookie Engineer's Web Log

This compact installation guide is meant as an overview article to skim through and remind myself of what's missing in an installation process. For any step, the Arch Wiki is much more comprehensible and has a lot of information on how to deal with error cases.

Familiarity with the cryptsetup tool and systemd-boot is required for this guide.

Boot Live ISO

1.1 USB flash drive

Download the image from the Arch Linux download page , flash it to the USB flash drive and then boot it on the target machine.

# replace /dev/sdX with the usb drive's identifier
sudo dd bs=4M conv=fsync oflag=direct status=progress if=/path/to/archlinux*.iso of=/dev/sdX;

1.2 Boot Live ISO

After bootup, set the timezones and the datetime correctly. All timezones are available in the /usr/share/zoneinfo folder, in case you can't find yours.

# list available timezones
# timedatectl list-timezones;

timedatectl set-ntp true;
timedatectl set-timezone Europe/Berlin;
timedatectl status;

Partition the Hard Drive

UEFI uses a GPT partition table, where you also have to have at least two partitions. Due to bugs and quirks of old BIOS versions, 512MB EFI partition size (which hosts both your kernel images and the EFI bootloader) is recommended, the second partition can be your / root partition.

I'll spare the whole bullshit about swapping partitions, the dangers of them and what kind of RAM your system has to have. You decide whether you wanna have swap space on your hard drive on your own. In my case all my systems have far beyond 16GB of RAM, so swapping pretty much never occurs and my operating modes never are rare on system memory.

2.1 Partition Table

fdisk /dev/sda;

# press g to create GPT partition table
# press n to add new partition (use `+512M` as size when asked)
# press t to change partition type to ESP/EFI and type `uefi` when asked

# press n to add new partition (use suggested size when asked)
# press t to change partition type to Linux and type `143` when asked
# press w to write to disk and exit

2.2 Format ESP/EFI Boot Partition

mkfs.fat -F 32 /dev/sda1;

2.3 Format LUKS Encrypted Partition

cryptsetup luksFormat /dev/sda2;
# Enter your password when asked

cryptsetup open /dev/sda2 root;
mkfs.ext4 /dev/mapper/root;

2.4 Mount Partitions

# Already did this earlier
# cryptsetup open /dev/sda2 root;

mount /dev/mapper/root /mnt;

mkdir -p /mnt/boot;
mount /dev/sda1 /mnt/boot;

2.5 Bootstrap Arch Linux

pacstrap /mnt base base-devel linux linux-firmware vim sudo;
genfstab -U /mnt > /mnt/etc/fstab;

arch-chroot /mnt;

Configure Arch Linux

IMPORTANT : Everything from here on out is executed inside the arch-chroot environment!

3.1 Configure Users

# Edit the /etc/sudoers file and uncomment the line `%wheel ALL=(ALL) ALL`.
vim /etc/sudoers;

3.2 Configure Locale

# Uncomment en_US.UTF-8
vim /etc/locale.gen;

echo "LANG=en_US.UTF-8" > /etc/locale.conf;
locale-gen;

3.3 Configure Timezone

ln -sf /usr/share/zoneinfo/Europe/Berlin /etc/localtime;
hwclock --systohc;

3.4 Configure Hostname

echo "myhostname" > /etc/hostname;

echo "127.0.0.1 localhost" > /etc/hosts;
echo "::1 localhost" >> /etc/hosts;
echo "127.0.1.1 myhostname" >> /etc/hosts;
echo "ff02::1 ip6-allnodes" >> /etc/hosts;
echo "ff02::2 ip6-allrouters" >> /etc/hosts;

3.5 Configure Nameservers

Add DNS nameservers to the /etc/resolv.conf file :

echo "nameserver 1.0.0.1" > /etc/resolv.conf;
echo "nameserver 1.1.1.1" >> /etc/resolv.conf;

3.6 Configure Admin User

# optionally give root user a password
passwd root;

useradd -m myusername;
usermod -aG users,wheel myusername;
passwd myusername;

Install Bootloader and Kernel Image

systemd-boot requires EFI and therefore can only be used if you chose the GPT/EFI Boot Partition option earlier.

4.1 Encrypt Hook

Add the encrypt hook to the HOOKS the right place before the filesystems hook into the /etc/mkinitcpio.conf file :

HOOKS=(base udev autodetect modconf kms block encrypt filesystems keyboard fsck)

4.2 Configure SystemD Bootloader

echo "default arch.conf" > /boot/loader/loader.conf;
echo "timeout 3" >> /boot/loader/loader.conf;
echo "editor no" >> /boot/loader/loader.conf;

Find out the UUID of the LUKS partition and replace the UUID variable later. The UUID of the sda2 partition is not the same as the one from the mounted ext4 partition, so be careful to not use the wrong one.

lsblk -f;

# example output
NAME     FSTYPE      FSVER LABEL UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
sda
├─sda1   vfat        FAT32       CAB5-B580                             366.3M    28% /boot
└─sda2   crypto_LUKS 2           4e31973f-1e77-4061-aadf-d77a057832b2
  └─root ext4        1.0         ce9d9c8c-90d4-4aea-bbf3-c345e21c2f8a     12G    90% /

Configure the Bootloader Entry for Arch Linux :

# You need to change this (see above):
export UUID="4e31973f-1e77-4061-aadf-d77a057832b2";

echo "title Arch Linux" > /boot/loader/entries/arch.conf;
echo "linux /vmlinuz-linux" >> /boot/loader/entries/arch.conf;
echo "initrd /initramfs-linux" >> /boot/loader/entries/arch.conf;
echo "options cryptdevice=UUID=$UUID:root root=/dev/mapper/root rw" >> /boot/loader/entries/arch.conf;

4.3 Regenerate Image and Install Bootloader

Regenerate the Linux Images and install the SystemD Bootloader :

mkinitcpio -P;
bootctl --esp-path=/boot --boot-path=/boot install;

Configure for Server Usage

5.1 Configure Network Interfaces

Arch Linux comes with SystemD, so it makes sense to reuse systemd-networkd . When you're running a server, you're probably using a LAN/ethernet cable.

In case you don't know your network interface's name, you can see that with ip addr .

Usually they are similar to enp0s25 , enp0s3 or eno1 , depending on your mainboard and its provided EFI settings (the name is derived from UEFI variables).

Change it accordingly in the config files below :

systemctl enable systemd-networkd;

5.2a DHCP Configuration

Edit the /etc/systemd/network/20-wired.network file :

[Match]
Name=enp0s25

[Network]
DHCP=yes

5.2b Static Configuration

Edit the /etc/systemd/network/20-wired.network file :

[Match]
Name=enp0s25

[Network]
Address=192.168.0.123/24
Gateway=192.168.0.1
DNS=192.168.0.1

5.3 Configure OpenSSH

Servers usually don't have a keyboard installed, so it makes sense to install OpenSSH now :

pacman -S openssh;
systemctl enable sshd.service;

Update and Reboot

6.1 Update Keyring

Sometimes the ISO can be outdated and keyrings will break later, and that's kind of annoying to debug. Make sure to update them before you reboot :

pacman -Sy archlinux-keyring;

6.2 Reboot

Exit the arch-chroot environment and go back to the USB live system shell, then restart the machine :

exit;
reboot;