# Difference between revisions of "USB flash installation media"

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This page discusses how to put Arch installation media onto a USB key (or "flash drive"). The result will be a LiveCD-like system that will discard all changes when it is shut down. If you would like to install and run Arch Linux on a USB key (ie. with persistent settings), see Installing Arch Linux on a USB key.

## On GNU/Linux

### Overwrite the USB drive

Beginning from release 2010.05, all ISO files can be directly written to USB media. Download them from your local mirror. To install, first ensure the USB device is unmounted and then issue the following command:

# dd if=archlinux.iso of=/dev/sd[x]


where archlinux.iso is the path to the ISO file and /dev/sd[x] is your USB device.

Note: You can also add bs=4M to speed up the dd process.
Warning: This will irrevocably destroy all data on /dev/sdx.
Warning: Make sure to use /dev/sdx and NOT /dev/sdx1. This is a very common error!

### Without overwriting the USB drive

With release 2011.08.19 or later, you can install the Arch image to USB without overwriting its contents. This is slightly more complicated than copying the image directly, but keeps the drive usable for data storage. Before you begin, make sure that your USB device is formatted as either FAT32, ext2/3/4 or btrfs (for interoperability with other operating systems, you probably want to use FAT32). Also make sure you have syslinux 4.04 installed (older or newer syslinux 4 versions may work, syslinux 3.XX will not work).

First, download and mount the ISO image:

$mount -o loop /path/to/image/archlinux-XXX.iso /path/to/iso/  Second, mount the USB drive and copy the contents of the /arch folder to its main directory: $ cp -r /path/to/iso/arch/ /path/to/usb/


The image also contains a /syslinux folder, but you do not need it.

Third, install syslinux to the USB drive:

$extlinux --install /path/to/usb/arch/boot/syslinux/  Next you will need to adjust the boot configuration files in order for your system to boot. From /path/to/usb/arch/boot/syslinux/*.cfg, replace: archisolabel=ARCH_201108  with either archisolabel=YOUR_USB_DRIVE_LABEL  or archisodevice=/dev/disk/by-uuid/YOUR_USB_DRIVE_UUID  Note: By using the UUID you are free to label your drive whatever you want (or you could leave it blank). Note: In the dual images this occurs in two places, while in the i686 and x86_64 images only once. Labels can be changed with e2label (for ext2/3/4) and dosfslabel (for FAT/FAT32): # e2label /dev/sdb2 ARCH_201108 # dosfslabel /dev/sdb2 ARCH_201108  If your USB drive has a partition table (most of them do), then you need to install an MBR and make the first partition active: Warning: If you choose the wrong device node here, you might destroy data, so be careful. $ dd bs=440 conv=notrunc count=1 if=/usr/lib/syslinux/mbr.bin of=/dev/sd[x]


where sd[x] is your USB drive's device node (the drive itself, not the first partition).

The partition table should look similar to this one:

\$ fdisk -l /dev/sd[x]
[...]
Device Boot      Start         End      Blocks   Id  System
/dev/sdx1   *        2048    15663103     7830528    b  W95 FAT32


As you can see, the first partition (sdx1) has the bootable flag set.

Your USB drive is now bootable.

Note: If you do not see the bootable flag at this point, you may try to manually set it. e.g: Using Gparted: right click on the partition > manage flags.
Note: This method will also work on Windows if you download the latest syslinux version for Windows. The commands will of course be different. Please refer to the syslinux documentation.

## On Mac OS X

To be able to use dd on your usb device on a Mac you have to do some special maneuvers. First of all insert your usb device, OS X will automount it, and run

diskutil list


in Terminal.app. Figure out what your usb device is called - mine was called /dev/disk1. (Just use the mount command or sudo dmesg | tail.) Now you run

diskutil unmountDisk /dev/disk1


to unmount the partitions on the device (i.e., /dev/disk1s1) while keeping the device proper (i.e., /dev/disk1). Now we can continue in accordance with the Linux instructions above (but use bs=8192 if you are using the OS X dd, the number comes from 1024*8).

 dd if=image.iso of=/dev/disk1 bs=8192
20480+0 records in
20480+0 records out
167772160 bytes transferred in 220.016918 secs (762542 bytes/sec)


it is probably a good idea to eject your drive before physical removal at this point.

 diskutil eject /dev/disk1


## On Windows

### Image Writer for Windows

Download win32 disk imager from http://launchpad.net/win32-image-writer. Run the program. Select the arch image-file and usb stick. The Win32 Disk Imager's file browser assumes image files end with .img, so if the image-file you have selected ends with .iso, you will have to type its name in manually; this difference in suffixes is simply cosmetic however, the image will be written fine regardless. Click on the write button. Now you should be able to boot from the usb stick and install Arch Linux from it.

### Linux Live USB Creator

Linux Live USB Creator can be used to create a bootable USB key for Arch either using a manually downloaded iso or automatically downloading the iso itself. It also supports automatic installation of VirtualBox on the USB key which can be used to boot Arch inside Windows. Visit home page for more info.

### The Universal USB Installer

Universal USB Installer is a Live Linux USB Creator that allows you to choose from a selection of Linux Distributions to put on your USB Flash Drive.

### The Flashnul Way

flashnul is an utility to verify the functionality and maintenance of Flash-Memory (USB-Flash, IDE-Flash, SecureDigital, MMC, MemoryStick, SmartMedia, XD, CompactFlash etc).

From a command prompt, invoke flashnul with -p, and determine which device index is your USB drive. For example, my output looks like this:

C:\>flashnul -p

Avaible physical drives:
Avaible logical disks:
C:\
D:\
E:\


In my case, it is drive E:

When you have determined which device is the correct one, you can write the image to your drive, by invoking flashnul with the device index, -L, and the path to your image. In my case, it would be

C:\>flashnul E: -L path\to\arch.iso


As long as you are really sure you want to write the data, type yes, then wait a bit for it to write. If you get an access denied error, close any Explorer windows you have open.

If under Vista or Win7, you should open the console as administrator, or else flashnul will fail to open the stick as a block device and will only be able to write via the drive handle windows provides

Note: Confirmed that you need to use drive letter as opposed to number. flashnul 1rc1, Windows 7 x64. -bgalakazam

### The Cygwin Way

Make sure your Cygwin installation contains the dd package. Or if you do not want to install Cygwin, you can simply download dd for windows from http://www.chrysocome.net/dd.

Place your image file in your home directory, in my case it is:

C:\cygwin\home\John\


Run cygwin as administrator (required for cygwin to access hardware). To write to your USB drive use the following command:

dd if=image.iso of=\\.\[x]:


where image.iso is the path to the iso-image file within the cygwin directory and \\.\[x]: is your USB device where x is the windows designated letter, in my case "\\.\d:".

On cygwin 6.0 find out the correct partition with

cat /proc/partitions


and write the ISO image with the information from the output. Example:

dd if=image.iso of=/dev/sdb

Warning: This will irrevocably delete all files on your USB stick, so make sure you do not have any important files on the stick before doing this.

### SYSLINUX: Boot the entire ISO from RAM using MEMDISK

This method is more suited for systems with more than 256 MB RAM. It uses the MEMDISK auxiliary module to load the entire ISO image in RAM. So if you plan on booting a dual image with core packages make sure you have at least 768 MB RAM available. Also, be prepared to wait a few seconds/minutes, depending how fast your RAM is, what ISO image you choose and how fast your USB stick is.

Format the USB stick as FAT32 and create the following folders:

X:\Boot
X:\Boot\ISOs
X:\Boot\Settings


Copy the ISO you'd like to boot to the ISOs folder (eg. archlinux-2011.08.19-netinstall-x86_64.iso).

Download syslinux-*.zip (4.05 is the latest right now) and copy:

./win32/syslinux.exe to the desktop, or wherever you want.

./memdisk/memdisk to the Settings folder, and while you're here create a "syslinux.cfg" file with the following contents:

DEFAULT arch_iso

LABEL arch_iso
MENU LABEL Arch Setup
LINUX memdisk
INITRD /Boot/ISOs/archlinux-2011.08.19-netinstall-x86_64.iso
APPEND iso


Tip: If you wanna add more distros (Debian and Parted Magic were tested) you could edit this file. Refer to the Syslinux wiki.

Create a *.bat (or *.cmd) file where "syslinux.exe" is located and run it:

@echo off
syslinux.exe -m -a -d /Boot/Settings X:


Done.

Note: If you get the famous 30 seconds error (especially with the i686 version), press the Tab key at the "Boot Arch Linux" entry and add "vmalloc=256M" at the end for the netinstall image and "vmalloc=448M" for the core image.

## After booting from the USB stick:

Start the installation by logging in as root and invoke the command "/arch/setup".

The installer should mount the source media automatically. If it fails you can manually mount the source media on the stick to the /src directory with the following command:

mount /dev/sd[x] /src