Archiso

An archiso profile contains configuration that defines the resulting ISO image. The profile structure is documented in /usr/share/doc/archiso/README.profile.rst.

Edit to select which packages are to be installed on the live system image, listing packages line by line.

To add packages not located in standard Arch repositories (e.g. custom packages or packages from AUR/ABS), set up a custom local repository and add your custom packages to it. Then add your repository to as follows:

To install packages from the multilib repository, simply uncomment that repository in .

The airootfs directory is used as the starting point for the root directory () of the live system on the image. All its contents will be copied over to the working directory before packages are installed.

Place any custom files and/or directories in the desired location under airootfs/. For example, if you have a set of iptables scripts on your current system you want to be used on you live image, copy them over as such:

$ cp -r /etc/iptables archlive/airootfs/etc

Similarly, some care is required for special configuration files that reside somewhere down the hierarchy. Missing parts of the directory structure can be simply created with mkdir(1).

By default, permissions will be for files and for directories. All of them will be owned by the root user. To set different permissions or ownership for specific files and/or folders, use the associative array in . See README.profile.rst for details.

Although both archiso's included profiles only have , ISOs can be made to include other or even multiple kernels.

First, edit to include kernel package names that you want. When mkarchiso runs, it will include all and work_dir/boot/initramfs-*.img files in the ISO (and additionally in the FAT image used for UEFI booting).

mkinitcpio presets by default will build fallback initramfs images. For an ISO, the main initramfs image would not typically include the hook, thus making an additional fallback image unnecessary. To prevent the creation of an fallback initramfs image, so that it does not take up space or slow down the build process, place a custom preset in . For example, for :

''archlive''/airootfs/etc/mkinitcpio.d/linux-lts.preset

PRESETS=('archiso')

ALL_kver='/boot/vmlinuz-linux-lts'
ALL_config='/etc/mkinitcpio.conf'

archiso_image="/boot/initramfs-linux-lts.img"

Finally create boot loader configuration to allow booting the kernel(s).

Archiso supports syslinux for BIOS booting and systemd-boot for UEFI booting. Refer to the articles of the boot loaders for information on their configuration syntax.

mkarchiso expects that systemd-boot configuration is in the directory, and syslinux configuration in and directories.

If you want to make your Archiso bootable on a UEFI Secure Boot enabled environment, you must use a signed boot loader. You can follow the instructions on Secure Boot#Booting an installation medium.

To enable systemd services/sockets/timers for the live environment, you need to manually create the symbolic links just as does it.

For example, to enable , which contains WantedBy=multi-user.target, run:

$ mkdir -p archlive/airootfs/etc/systemd/system/multi-user.target.wants
$ ln -s /usr/lib/systemd/system/gpm.service archlive/airootfs/etc/systemd/system/multi-user.target.wants/

The required symlinks can be found out by reading the systemd unit, or if you have the service installed, by enabling it and observing the systemctl output.

Starting X at boot is done by enabling your login manager's systemd service. If you do not know which .service to enable, you can easily find out in case you are using the same program on the system you build your ISO on. Just use:

$ ls -l /etc/systemd/system/display-manager.service

Now create the same symlink in . For LXDM:

$ ln -s /usr/lib/systemd/system/lxdm.service archlive/airootfs/etc/systemd/system/display-manager.service

This will enable LXDM at system start on your live system.

The configuration for getty's automatic login is located under .

You can modify this file to change the auto login user:

[Service]
ExecStart=
ExecStart=-/sbin/agetty --autologin username --noclear %I 38400 linux

Or remove it altogether to disable auto login.

To create a user which will be available in the live environment, you must manually edit , , and .

For example, to add a user archie. Add them to following the syntax:

''archlive''/airootfs/etc/passwd

root:x:0:0:root:/root:/usr/bin/zsh
archie:x:1000:1000::/home/archie:/usr/bin/zsh

Generate a password hash with and add it to following the syntax of . For example:

Add the user's group and the groups which they will part of to according to . For example:

Create the appropriate according to :

Make sure /etc/shadow and have the correct permissions:

''archlive''/profiledef.sh

...
file_permissions=(
  ...
  ["/etc/shadow"]="0:0:0400"
  ["/etc/gshadow"]="0:0:0400"
)

After package installation, mkarchiso will create all specified home directories for users listed in and copy to them. The copied files will have proper user and group ownership.

Start by copying the file into the folder in the rootfs. Then, edit the file accordingly. You can also change the name inside of GRUB and syslinux.

The temporary files are copied into work directory. After successfully building the ISO , the work directory and its contents can be deleted. E.g.:

# rm -rf /path/to/work_dir

If you do not have an arch system available or you need to setup Archiso from another GNU/Linux distribution, be aware there exists an online builder.

To install Arch Linux via SSH without any interaction with the system, an SSH public key must be placed in .

Adding the SSH key can either be done manually (explained here), or by cloud-init.

To add the key manually, first copy Archiso's releng profile to a writable directory. The following example uses .

$ cp -r /usr/share/archiso/configs/profile/ archlive

Create a .ssh directory in the home directory of the user which will be used to log in. The following example will be using the root user.

$ mkdir archlive/airootfs/root/.ssh

Add the SSH public key(s), which will be used to log in, to :

$ cat ~/.ssh/key1.pub >> archlive/airootfs/root/.ssh/authorized_keys
$ cat ~/.ssh/key2.pub >> archlive/airootfs/root/.ssh/authorized_keys

Set correct permissions and ownership for the .ssh directory and the file:

Finally build the ISO. Upon booting the ISO, OpenSSH will start and it will be possible to log in using the corresponding SSH private key(s).

Create inside the profile's directory and set the correct permissions:

$ mkdir -p archlive/airootfs/var/lib/iwd

Follow the instructions in iwd#Network configuration and to create a network configuration file for your Wi-Fi network.

Save the configuration file inside .

When installing packages on a live Archiso, for example on hardware requiring DKMS modules, the default size of the Archiso might not allow the download and installation of such packages due to its size.

It will manifest as the following error message when downloading files or installing packages in the live environment:

error: partition / too full: 63256 blocks needed, 61450 blocks free
error: not enough free disk space
error: failed to commit transaction (not enough free disk space) 
Errors occurred: no packages were upgraded.

You can also adjust the root partition size on the fly by running:

# mount -o remount,size=2G /run/archiso/cowspace

To adjust the size of the root partition on the live Arch Linux system before booting it, press the Tab key to edit the kernel parameters. Append at the end to get 2G size for the root partition. Press to continue booting into the live system. You can check the size of the filesystems by running:

$ df -h

See more boot parameters here

In order for vanilla to produce encrypted images, LUKS support in archiso, encrypt hook's compatibility in mkinitcpio-archiso and nested cryptkeys support in merge requests need to be approved.

Packages with such features already merged are , and .

To enable encryption on an existing profile:

• add to the value in ;
• set an in (to use a key file instead of a password).
• enable the encrypt hook in ;
• add AUR packages (or build custom replacements with the aforementioned sources) to
• add the keys buildmode to the array in (to build a second ISO containing the key file that put on external storage is able to boot the system).

Example configurations based on the and profiles are available as and in the archiso-profiles^AUR package.

A Google Compute Engine-compatible compressed image is available as .

A libvirt configuration which runs the image is available as archlinux-libvirt^AUR.

If you want to use a window manager in the Live CD, you must add the necessary and correct video drivers, or the WM may freeze on loading.