This page explains how to install Arch Linux on a USB flash drive. The end result is a persistent installation identical to that on a normal hard drive along with several performance optimizations aimed at running Linux on removable flash media. It is compatible with both BIOS and UEFI booting modes.

The only packages explicitly installed are linux, linux-firmware, base, efibootmgr, grub, iwd, polkit, sudo, and vim. Basic services are handled by systemd.

Install Base System

Determine the target USB device name:

For the remainder of this guide, the device name will be referred to as /dev/sdX.

wipe (optional)

Use dd to write the USB with all zeros, permanently erasing all data:

Expect this to take a relatively long time (hour+) depending on the size of the USB.

partition

format

Do not format the /dev/sdX1 block. This is the BIOS/MBR parition.

Format the 500MB EFI system partition with a FAT32 filesystem:

Format the Linux partition with an ext4 filesystem:

mount

Mount the ext4 formatted partition as the root filesystem:

Mount the FAT32 formatted EFI partition to /boot:

pacstrap

Download and install the Arch Linux base packages:

fstab

Generate a new /etc/fstab using UUIDs as source identifiers:

Configure Base System

Unless otherwise noted, all configuration is done within a chroot. Chroot into the new system:

Exit the chroot environment when finished by typing exit.

locale

Use tab-completion to discover the appropriate entries for region and city:

Edit /etc/locale.gen and uncomment the desired language (for US English, uncomment en_US.UTF-8 UTF-8):

Generate the locale information:

Set the LANG variable in /etc/locale.conf (for US English, localeline is en_US.UTF-8):

time/date

Generate /etc/adjtime:

hostname

Create a /etc/hostname file containing the desired hostname on a single line:

Edit /etc/hosts to contain only the following content:

127.0.0.1  localhost
::1        localhost
127.0.1.1  hostname.localdomain  hostname

password

Set the root password:

bootloader

Install grub and efibootmgr:

Install GRUB for both BIOS and UEFI booting modes:

Generate a GRUB configuration:

networking

Create a networkd configuration file with the following content to automatically establish wired connections:

[Match]
Name=en*
Name=eth*

[Network]
DHCP=yes
IPv6PrivacyExtensions=yes

[DHCPv4]
RouteMetric=10

[IPv6AcceptRA]
RouteMetric=10

Enable networkd:

Install and enable iwd to allow user control over wireless interfaces:

Create a networkd configuration file with the following content for wireless connections:

[Match]
Name=wl*

[Network]
DHCP=yes
IPv6PrivacyExtensions=yes

[DHCPv4]
RouteMetric=20

[IPv6AcceptRA]
RouteMetric=20

Enable resolved:

NOTE: this command must be done outside of the chroot environment. Create link to /run/systmed/resolve/stub-resolv.conf:

Enable timesyncd:

user

Create a new user account and set its password:

Ensure the wheel group exists and add user to it:

sudo

Install sudo:

Enable sudo for the sudo group by creating a rule in /etc/sudoers.d/:

Ensure the sudo group exists and add user to it:

Install polkit to allow various commands (reboot and shutdown, among others) to be run by non-root users:

noatime (optional)

Decrease excess writes to the USB by ensuring its filesystems are mounted with the noatime option. Open /etc/fstab in an editor and change each relatime or atime option to noatime:

# /dev/sdX3
UUID=uuid1  /      ext4  rw,noatime      0 1

# /dev/sdX2
UUID=uuid2  /boot  vfat  rw,noatime,...  0 2

journal (optional)

Prevent the systemd journal service from writing to the USB by configuring it to use RAM. Create a drop-in config file with the following content:

[Journal]
Storage=volatile
SystemMaxUse=16M
RuntimeMaxUse=32M

mkinitcpio (optional)

Ensure needed modules are always included in the initcpio image. Remove autodetect from HOOKS in /etc/mkinitcpio.conf:

...
HOOKS=(base udev modconf block filesystems keyboard fsck)
...

Disable fallback image generation (it is identical to the default image without the autodetect hook). Remove fallback from PRESETS in /etc/mkinitcpio.d/linux.preset:

...
PRESETS=('default')
...

Remove the existing fallback image:

Generate a new initcpio image:

Generate a new GRUB configuration:

nomodeset (optional)

Create a GRUB menu item with the nomodeset kernel parameter. Use vim to copy the default menuentry from /boot/grub/grub.cfg into /etc/grub.d/40_custom and add nomodeset to its kernel command line:

...
menuentry 'Arch Linux ... (nomodeset)' ...
...
linux /vmlinuz-linux ... nomodeset
...

Generate a new GRUB configuration:

microcode (optional)

Enable microcode updates. Install amd-ucode and intel-ucode:

Rebuild boot images:

interface names (optional)

Ensure that main ethernet and wifi interfaces are always named eth0 and wlan0. Revert to traditional device naming: