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 while using the instructions at the Installation guide.
- Before creating the initial RAM disk, in
keyboardhooks before the
autodetecthook. This is necessary to allow booting on multiple systems each requiring different modules in early userspace.
- It is highly recommended to review the reduce disk reads/writes 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.
- 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.
- 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.
- When GRUB is installed on the USB key, the key will always be
- It seems that current versions of GRUB will automatically default to using uuid. The following directions are for GRUB legacy.
menu.lst, the GRUB legacy configuration file, should be edited to (loosely) match the following.
When using label your menu.lst should look like this:
root (hd0,0) kernel /boot/vmlinuz-linux root=/dev/disk/by-label/Arch rw 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 rw 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 --removable --recheck
Using your UUID:
LABEL Arch MENU LABEL Arch Linux LINUX ../vmlinuz-linux APPEND root=UUID=3a9f8929-627b-4667-9db4-388c4eaaf9fa rw INITRD ../initramfs-linux.img
Using your USB install on multiple machines
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.
nomodesetas a kernel parameter as a preemptive measure you may have to adjust the display resolution manually when using machines with Nvidia video cards. See Xrandr 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 systemd journal 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 to avoid such system calls:
$ eatmydata firefox