When installing a linux distribution, it is common for the instructions to have the user create a bootable USB, boot from the device, and proceed with the installation procedure from that live medium. However, this blog post will outline an alternative approach where a virtual machine created with Vagrant will be used in favor of the live medium.

Preface

The original intention was to use Docker for this process -- leveraging the --device flag and mounting the target USB device in the Docker container, but the underlying hypervisor in Docker Desktop for Mac does not support this. ^{1 2 3} While there are workarounds using Docker Machine, Vagrant felt like the path of least resistance.

Instructions

Create an Arch Linux Virtual Machine with Vagrant

Get the latest Arch Linux image ⁴ from the Vagrant Cloud Box Catalog.

vagrant box add archlinux/archlinux

Determine the USB vendor information for the thumb-drive that we will pass-through to the virtual machine. Using the VBoxManage utility that comes with Virtual Box, list the devices, and make note of the Vendor and Product ID.

 VBoxManage list usbhost

Create a Vagrantfile with archlinx/archlinux as the target box, and the USB device information that is passed through. ^{5 6} Vagrant offers a handy customization parameter vb.customize that calls the VBoxManage command under-the-hood, allowing one to enable the guest machine to access the host machine's USB devices.

# -*- mode: ruby -*-
# vi: set ft=ruby :

Vagrant.configure("2") do |config|
  config.vm.box = "archlinux/archlinux"
  config.vm.provider "virtualbox" do |vb|
    vb.name = "archlinux"
    vb.customize ['modifyvm', :id, '--usb', 'on']
    vb.customize ['usbfilter', 'add', '1', '--target', :id, '--name', 'SanDisk Ultra Fit', '--vendorid', '0x0781', '--productid', '0x5583']
  end
end

When virtual machine is brought up, the usbfilter is applied, and the guest is able to access to the host machine's USB device that was specified in the filter.

Start the machine, ssh into the guest, and list the devices to confirm that the USB device is available (see: /dev/sdb).

$ vagrant up
$ vagrant ssh
[vagrant@archlinux ~]$ lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0   20G  0 disk
├─sda1   8:1    0  1.9G  0 part [SWAP]
└─sda2   8:2    0 18.1G  0 part /
sdb      8:16   1 28.7G  0 disk
└─sdb1   8:17   1    8G  0 part

Install Arch Linux on the USB Drive

The Arch Linux Installation Guide outlines the installation procedure in great detail -- the following steps follow this closely with a few alteration due to installing onto removable media.

Partition the Disk (UEFI with GPT)

[root@archlinux ~]# fdisk /dev/sdb

Command (m for help): p
Disk /dev/sdb: 28.66 GiB, 30752636928 bytes, 60063744 sectors
Disk model: Ultra Fit
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: E1D6C445-1B79-AB4D-A442-FA4AD6DF4ECC

Device       Start      End  Sectors  Size Type
/dev/sdb1     2048  1050623  1048576  512M EFI System
/dev/sdb2  1050624 60063710 59013087 28.1G Linux filesystem

Filesystem/RAID signature on partition 1 will be wiped.

Format the Partitions

The UEFI specification mandates support for FAT file-systems, and FAT32 is recommended for removable media. ⁷

[root@archlinux ~]# pacman -Sy dosfstools
[root@archlinux ~]# mkfs.fat -F32 /dev/sdb1

As for the root partition, it is recommended to use ext4 without a journal to reduce the reads and writes to the file-system as this is detrimental to the flash-based USB drive. ⁸

[root@archlinux ~]# mkfs.ext4 -O "^has_journal" /dev/sdb2

Mount the Partitions and Bootstrap the Environment

[root@archlinux ~]# mount /dev/sdb2 /mnt
[root@archlinux ~]# mkdir -p /mnt/boot/efi
[root@archlinux ~]# mount /dev/sdb1 /mnt/boot/efi

[root@archlinux ~]# pacman -S arch-install-scripts
[root@archlinux ~]# pacstrap /mnt base linux linux-firmware
[root@archlinux ~]# genfstab -U /mnt >> /mnt/etc/fstab

Configure the New Environment

[root@archlinux ~]# arch-chroot /mnt

[root@archlinux /]# ln -sf /usr/share/zoneinfo/US/Eastern /etc/localtime
[root@archlinux /]# hwclock --systohc
[root@archlinux /]# sed -i 's/#en_US.UTF-8/en_US.UTF-8/' /etc/locale.gen
[root@archlinux /]# locale-gen
[root@archlinux /]# echo "LANG=en_US.UTF-8" > /etc/locale.conf

[root@archlinux /]# hostnamectl set-hostname usb
[root@archlinux /]# echo "127.0.0.1        localhost" >> /etc/hosts
[root@archlinux /]# echo "::1              localhost" >> /etc/hosts

Note, one difference here from a standard installation is that the --removable flag is specified when installing the GRUB bootloader. ¹⁰

[root@archlinux /]# pacman -S grub
[root@archlinux /]# grub-install --target=x86_64-efi --efi-directory=/boot/efi  --removable --recheck
[root@usb /]# grub-mkconfig -o /boot/grub/grub.cfg

Shutdown the virtual machine, restart the host machine, and boot the newly created Arch Linux thumb-drive!

🎉

Side-note

It was attempted to use the controlvm usbattach command to pass the USB device to the guest machine, but this did not work as it expects the virtual machine to already be running, and the vb.customize option runs prior to booting the machine. ¹¹

Command: ["controlvm", "060a716b-1965-49e2-bc56-12beed5df716", "usbattach36fc9e60-c465-11cf-8056-444553540000"]

Stderr: VBoxManage.exe: error: Machine '060a716b-1965-49e2-bc56-12beed5df716' is not currently running.

Create a Persistent Arch Linux Bootable USB with Vagrant