Installing Arch Linux on a USB key
This page explains how to perform a regular Arch installation onto a USB key (or "flash drive"). In contrast to having a LiveUSB as covered in USB flash installation media, the result will be a persistent installation identical to normal installation to HDD, but on a USB flash drive.
- 1 Installation
- 2 Configuration
- 3 Tips
- 4 See also
There are various ways of installing Arch on a USB stick, depending on the operating system you have available:
- If you have another Linux computer available (it need not be Arch), you can follow the instructions at Install from existing Linux.
- An Arch Linux CD/USB can be used to install Arch onto the USB key, via booting the CD/USB and following the installation guide. If booting from a Live USB, the installation will have to be made on a different USB stick.
- If you run Windows or OS X, download VirtualBox, install VirtualBox Extensions, add the USB drive to a virtual machine running Arch (for example running from an iso), point the installation into the USB drive.
Follow the installation guide as you normally would, with these exceptions:
- If cfdisk fails with "Partition ends in the final partial cylinder" fatal error, the only way to proceed is to kill all partitions on the drive. Open another terminal (
sdXis your usb drive), print partition table (p), check that it's ok, delete it (d) and write changes (w). Now return to cfdisk.
- It is highly recommended to review the tips for minimizing disk reads/writes on the SSD wiki article prior to selecting a filesystem. To sum up, ext4 without a journal should be fine, which can be created with
# mkfs.ext4 -O "^has_journal" /dev/sdXX. The obvious drawback of using a filesystem with journaling disabled is data loss as a result of an ungraceful dismount. Recognize that flash has a limited number of writes, and a journaling file system will take some of these as the journal is updated. For this same reason, it is best to forget the swap partition. Note that this does not affect installing onto a USB hard drive.
- Before creating the initial RAM disk
# mkinitcpio -p linux, in
blockhook to the hooks array right after udev. This is necessary for appropriate module loading in early userspace.
- If you want to be able to continue to use the UFD device as a cross-platform removable drive, this can be accomplished by creating a partition housing an appropriate file system (most likely NTFS or exFAT). Note that the data partition may need to be the first partition on the device, as Windows assumes that there can only be one partition on a removable device, and will happily automount an EFI system partition otherwise. Remember to install and . Some tools are available online that may allow you to flip the removable media bit on your UFD device. This would trick operating systems into treating your UFD device as an external hard disk and allow you to use whichever partitioning scheme you choose.
- Install NetworkManager to control networks, it supports changing interface names of different hardware.
- Make sure that
/etc/fstabincludes the correct partition information for
/, and for any other partitions on the USB key. If the usb key is to be booted on several machines, it is quite likely that devices and number of available hard disks vary. So it is advised to use UUID or label:
To get the proper UUIDs for your partitions issue blkid
menu.lst, the GRUB legacy configuration file, should be edited to (loosely) match the following:
With the static
root (hd0,0) kernel /boot/vmlinuz-linux root=/dev/sda1 ro initrd /boot/initramfs-linux.img
When using label your menu.lst should look like this:
root (hd0,0) kernel /boot/vmlinuz-linux root=/dev/disk/by-label/Arch ro initrd /boot/initramfs-linux.img
And for UUID, it should be like this:
root (hd0,0) kernel /boot/vmlinuz-linux root=/dev/disk/by-uuid/3a9f8929-627b-4667-9db4-388c4eaaf9fa ro initrd /boot/initramfs-linux.img
On GPT with UEFI installations, make sure you follow the instructions on GRUB#UEFI systems and include the --removable option as doing otherwise may break existing GRUB installations, as in the below command:
# grub-install --target=x86_64-efi --efi-directory=$esp --bootloader-id=grub --removable --recheck
With the static
LABEL Arch MENU LABEL Arch Linux LINUX ../vmlinuz-linux APPEND root=/dev/sdax ro INITRD ../initramfs-linux.img
Using your UUID:
LABEL Arch MENU LABEL Arch Linux LINUX ../vmlinuz-linux APPEND root=UUID=3a9f8929-627b-4667-9db4-388c4eaaf9fa ro INITRD ../initramfs-linux.img
Using your USB install on multiple machines
For the most versatile compatibility it is recommended that you install the i686 architecture because it will run on both 32-bit (i686) and 64-bit (x86_64) architectures.
Additionally, due to the reduced size of 32-bit binaries and the absence of (possible) multilib packages, an i686 installation typically consumes less space than an equivalent x86_64 one.
For laptop use (or use with a tactile screen) you will need thepackage for the touchpad/touchscreen to work.
For instructions on fine tuning or troubleshooting touchpad issues, see the Touchpad Synaptics article.
To support most common GPUs, install, , , and .
Persistent block device naming
Alternatively, you may create udev rule to create custom symlink for your usb key. Then use this symlink in fstab and bootloader configuration. See udev#Setting static device names for details.
You may want to disable KMS for various reasons, such as getting a blank screen or a "no signal" error from the display, when using some Intel video cards, etc. To disable KMS, add
nomodeset as a kernel parameter. See Kernel parameters for more info.
Booting from USB 3 media
The fallback image should be used for maximum compatibility.
Minimizing disk access
- You may want to configure journald to store its journals in RAM, e.g. by creating a custom configuration file:
[Journal] Storage=volatile RuntimeMaxUse=30M
- To disable
fsyncand related system calls in web browsers and other applications that do not write essential data, use the eatmydata command from AUR to avoid such system calls:
$ eatmydata firefox