Choosing the Right Installation Medium

Available Options

Architecture

Computer hardware, and CPUs in particular, come in several different architectures. A very common consumer architecture is known as x86_64 - the traditional Intel x86 architecture with AMD’s 64-bit extensions. If you are installing Alpine to a traditional computer, this is most likely what you have. However, Alpine supports several other architectures for to-disk installation purposes:

x86_64: the most common desktop, laptop and server architecture
x86: the older variant of x86_64, increasingly more rare, and limited to 4gb of ram
ppc64le: OpenPower-based systems, such as IBM’s POWER8
s390x: IBM Z (Mainframes)

Under some circumstances, you may also use armhf and aarch64 architectures - relevant to ARM chips, 32bit and 64bit respectively, the latter of which may support UEFI.

Image Type

Alpine offers a variety of downloadable images.

The image varieties relevant to this handbook are as follows:

standard: A minimal installation image. Requires networking.
extended: Standard, but with additional packages included. Fewer available architectures, but may be more convenient. Often used for non-disk installations.
netboot: A netboot image, intended to be used with PXE. Using PXE is outside the scope of this handbook, but it may be used in place of the standard image.
virtual: The standard image, but using a different kernel, optimized for virtual environments.
xen: Specialized image, intended to be used in xen dom0 installations.

If you aren’t sure what image to use, you should use extended, assuming your architecture is supported and your boot device is large enough. Otherwise, you should use the standard image.

Downloading

Obtaining the Chosen Media

Image downloads are available at alpinelinux.org. Press the button under your chosen image type, that corresponds to your target architecture. This will link to a direct download of your image.

If your download has a suffix that is not .iso, this means that you have selected an image type or architecture that does not support booting directly. If that is the case, stop reading here, and either seek help as is outlined at the start of this handbook, or refer to the wiki on what to do with the file you acquired.

[Recommended] Verifying the Downloaded Files (sha256)

To ascertain that the files you downloaded are intact, you can calculate what is known as a "hash sum" of the file, and compare it to the publicly known one. Next to the download button you clicked, there is a separate one with "sha256" written on it - this is a direct download to a (very small) file that contains said public hash.

[Linux] Sha256 Calculation

On a Linux host, you can calculate the sha256 hashsum of a given file using the sha256 utility. Here is an example command you can enter in your shell to calculate the sha256 sum of a file named "alpine.iso" in your current directory.

sha256sum alpine.iso

[MacOS] Sha256 Calculation

On a MacOS host, you can calculate the sha256 hashsum of a given file using the shasum utility. Here is an example command you can enter in your shell to calculate the sha256 sum of a file named "alpine.iso" in your current directory.

shasum -a 256 alpine.iso

[Windows] Sha256 Calculation

On a Windows host, you can calculate the sha256 hashsum of a given file using the Get-FileHash PowerShell utility. Here is an example command you can enter in PowerShell to calculate the sha256 sum of a file named "alpine.iso" in your current directory.

Get-FileHash .\alpine.iso -Algorithm SHA256

[Optional] Verifying the Downloaded Files (PGP)

To ascertain that the files you downloaded are intact, and signed by the developers, you can use the signature file, and verify its validity against the public key of the signer, as well as the contents of the image. Next to the button you clicked, there is a separate one with "GPG" written on it - this is a direct download to a (very small) file that contains said signature.

Currently, signatures are made by ncopa, whose key is available over at alpinelinux.org. You should download and import this key, or import it into your PGP keychain some other way.

Assuming you have GnuPG (a PGP implementation) installed, you can verify the signature "alpine.iso.asc" of a file named "alpine.iso" signed by "ncopa.asc" in a shell as so:

gpg --import ncopa.asc
gpg --verify alpine.iso.asc alpine.iso

Using the Image

A .iso file on its own is not very useful. You can either flash it to a usb stick, or burn it to a physical cd/dvd.

USB Drive

On Windows and MacOS hosts, it is most convenient to use a dedicated utility, such as Etcher. See that project’s documentation in case any further details are required.

On Linux hosts, such utilities have many dependencies and might not be installed by default. As such, it is also possible to use the dd utility. You must figure out the physical "device node" of your USB drive. This will usually be in the form of /dev/sdX, where X is a lowercase letter, such as a, b or c.

The next step will permanently erase all data on the selected device. Please be very sure you have identified the correct device before proceeding.

Once you have identified your device, you can flash a file named "alpine.iso" to your device (/dev/sdb in this example) using the following command:

dd if=alpine.iso of=/dev/sdb (1)

1	This needs to be run as root, unless your user has write access to the output block device.

You may achieve greater performance in this operation by passing additional parameters, such as bs=1M. You can find more details on those in the dd manual page (dd(1)).

Burning to a CD/DVD

Another way to utilize the .iso file is by burning it on a CD or DVD. This is also useful on older systems that do not know how to boot from a USB drive.

On MacOS, you can select the .iso file, and then press File Burn Disk Image […].

On Windows 8 and above, you can right-click the .iso file, and then press Burn Disk Image.

On Linux hosts, there are no default built-in tools to burn images.

[Linux] Burning an Image File

This handbook recommends using k3b - a graphical utility inside of which one can select Tools Burn CD Image.

Alternatively, people that do not wish to use a graphical environment for this, might want to use the cdrtools program. Here is an example command that will burn an image named alpine.iso to the first found disk drive (/dev/sr0):

cdrecord dev=/dev/sr0 alpine.iso (1)

1	This needs to be run as root, unless your user has write access to the output block device.

Booting

Once you have prepared your appropriate installation medium, you need to boot into the Alpine Linux live environment. During the bootup of your system, you should have the option to enter BIOS/UEFI settings, alongside what is often called "One Time Boot Override", or "Boot Selection".

If you can identify the button to press to get that latter one, you should mash it, and select the entry that corresponds to your installation medium. Alternatively, you can try mashing the button for BIOS/UEFI settings, and changing the boot order (often allowed) to prioritize your medium. If it is unclear which button it is, you can try any of these, which are commonly used for all of those purposes: DEL F1 F10 ESC

If you want to install Alpine in UEFI (non-legacy, nor BIOS) mode, you must use UEFI to boot the USB disk.

[Optional] Modifying Kernel Command Line

There are some scenarios in which you will need to modify the kernel command line. You might even need to do so for diagnostic reasons. You can see what parameters are available and what they do over at the Developer Handbook.

One common reason to modify the kernel command line is to explicitly tell linux to not trust the CPU’s randomness generator, which Alpine trusts by default. While the reasons for doing so won’t be discussed here, doing so means that you will need to gather entropy from other sources. If you still wish to disable it, you may add random.trust_cpu=off to your kernel’s command line on boot.

[Grub] Modifying Kernel Command Line

Under grub, when you are presented with the boot prompt, you may press e to edit the booting configuration. You can then find the line starting with linux, and add or remove parameters from that line.

[Isolinux] Modifying Kernel Command Line

Under isolinux, there is no graphical editor, but you can specify the kernel command line directly. To do so, you must select the correct label (for example, lts or virt), and add your parameters there. For example, if you wanted to add rootflags=noatime to your kernel command line, your isolinux prompt should look as so:

boot: lts rootflags=noatime