Installation

From Alpine Linux




This page explains the basics to get started. But before actually installing, it can also help to skim through the Frequenty Asked Questions (FAQ).


Minimal Hardware Requirements

  • At least 100 MB of RAM. [A graphical desktop system may require up to 1 GB minimum.]
  • At least 0-700 MB space on a writable storage device. [Only required in "sys" or "data" mode installations (explained below). It is optional in "diskless" mode, to save newer data states and configurations of a running system.]

Installation Overview

The general course of actions

[Note: For single-board-computer (SBC) architectures which can not boot .iso images, see e.g. Alpine on ARM for peculiarities.]


As usual, the regular installation procedure starts with three basic steps (additional details for all the steps follow below):


1.) Downloading and verifying the proper stable-release ISO installation image-file for the computer's architecture, and the corresponding sha256 (checksum) and GPG (signature) files.

2.) Either burning the ISO image-file onto a blank CD/DVD/Blu-ray disk with a disk burning software, or flashing the installation image onto a bootable storage device (USB-device, CF-/MMC-/SD-card, floppy, ...).

3.) Booting the computer from the prepared disk or storage device.


The boot process then copies the entire operating system into the RAM, and then runs it completely from RAM. This means that the running command line environment does not depend on reading from the (possibly slow) initial boot media anymore.

Log-in is possible as the user root with its initially empty password.

Then an interactive script called setup-alpine can be called from the command line, to configure and install the initial Alpine Linux system. Alternatively, it's also possible to use more specific setup-scripts, the apk package manager, and all the general command line tools to set things up. For example, to install a special package requirement to prepare the system before running the interactive setup-alpine script. Or, to fine-tune a newly installed system's configuration right after the install before it starts up for the first time.

Note that setup-alpine can configure the system to boot into one of three Alpinelinux disk modes, "diskless", "data", and "sys":

Diskless Mode

This is the default boot mode of the .iso images, and setup-alpine configures this if selecting to install to "disk=none". It means that the whole operating system and all applications are loaded into the RAM, and run extremely fast (saving unnecessary disk spin-ups, power, and wear). Customized configurations and package selections may stil be preserved on permanent storage media by saving a local backup with lbu --commit and enabling a local package cache.

[FIXME-1: This still needs some manual steps to prepare a partition before running setup-alpine.]

In setup-alpine, select to store configs and the package cache on a partition. (The same partition may later also be used by configuring some important applications to keep their data run-time data on it.)

The system's boot device may remain the initial installation image, and could even be or be set immutable (read-only).

Data Disk Mode

This mode is still accelerated by running the system from RAM, however swap storage and the whole /var directory tree gets mounted from a persistent storage device (two newly created partitions). This location holds e.g. all log files, mailspools, databases, etc., as well as lbu backup commits and the package cache. The mode is useful for having RAM accelerated servers with amounts of variable user-data that exceed the available RAM size, and to let the entire current system state (not just the boot state) survive a system crash according to the particular filesystem's guarantees.

[FIXME-2: Storing lbu configs to the "data disk" can not be auto-configured after configuring the data partition. One must still first select to save configs to "none" (the new data partition is not listed), and has to manually edit /etc/lbu/lbu.conf to set e.g. LBU_MEDIA=sda2, execute a corresponding echo "/dev/sda2 /media/sda2 vfat rw 0 0" >> /etc/fstab afterwards, and save the config with lbu commit to have the partition (here sda2) mounted when booting.]

In this mode, the boot device may also remain the initial installation image and read-only.

System Disk Mode

This is a traditional hard-disk install. If this mode is selected, the setup-alpine script defaults to create three partitions on the selected storage device, /boot, swap and / (the filesystem root). This mode may be used for generic desktop and development machines, for example.

Additional Details

This material needs expanding ...

This "Additional Details" section needs to be consolidated with the work at https://docs.alpinelinux.org (not finished) (Restructuring things there, moving and linking from here or there?).


Verifying the downloaded image-file

Commands to verify the checksum and GPG signature of a downloaded image-file on different systems.
OS type SHA256 check SHA256 calculation (to be compared manually) GPG signature verification
Linux sha256sum -c alpine-*.iso.sha256 curl https://alpinelinux.org/keys/ncopa.asc | gpg --import ;

gpg --verify alpine-<version>.iso.asc alpine-<version>.iso

MACOS - ? - shasum -a 256 alpine-*.iso - ? -
BSD - ? - /usr/local/bin/shasum -a 256 alpine-*.iso - ? -
Windows (PowerShell installed) - ? - Get-FileHash .\alpine-<image-version>.iso -Algorithm SHA256 - ? -

Flashing (direct data writing) the installation image-file onto a device or media

Under Unix (and thus Linux), "everything is a file" and the data in the image-file can be written onto a device or media with the dd command. Afterwards, eject can remove the target device from the system, to ensure the completion of all writes and clearing of the cache.

dd if=<iso-file-to-read-in> of=<target-device-node-to-write-out-to> bs=4M oflag=sync status=progress; eject <target-device-node-to-write-out-to>

Be careful to correctly identify the target device to overwrite, because all previous data on it will be lost! All connected "bulk storage devices" can be listed with lsblk.

$ lsblk
NAME            MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sdX               0:0    0  64,0G  0 disk  
├─sdX1            0:1    0     2G  0 part  
└─sdX2            0:2    0    30G  0 part  /mnt/sdX2


For example, if /dev/sdX is the desired target device to write the image to here, then first make sure to un-mount all mounted partitions of the target device individually. For example sdX1 and sdX2.

umount  /dev/sdX1  /dev/sdX2


For dd's out-file (of=), however, do not specify a partition number. For example, write to sdX and not sdX1:

Warning: This will completely erase the target device /dev/sdX, so before executing, make sure to really have a backup of the data if still need.

dd if=~/Downloads/alpine-standard-3.00.0-x86_64.iso of=/dev/sdX bs=4M oflag=sync status=progress; eject /dev/sdX

Verifying the written installation media

After detaching and re-attaching the device, a bit-wise comparison can verify what has been written to the device (instead of just data buffered in RAM). If the comparison terminates with an end-of-file error on the .iso file side, all the contents from the image has been written (and read again) successfully:

# cmp ~/Downloads/alpine-standard-3.00.0-x86_64.iso /dev/sdX
cmp: EOF on alpine-standard-3.00.0-x86_64.iso

Booting from external devices

Insert the boot media to a proper drive or port of the computer and turn the machine on, or restart it, if already running.

If the computer does not automatically boot from the desired device, one needs to bring up the boot menu selection for choosing the media to boot from. Depending on the computer the menu may be accessed by quickly (repeatedly) pressing a key when booting starts, or sometimes it is needed to press the button before starting the computer and keep holding it when it boots. Typical keys are: `F9`-`F12`, sometimes `F7` or `F8`. If these don't bring up the boot menu, it may be necessary to enter the BIOS configuration and adjust the boot settings, for which typical keys are: `Del.` `F1` `F2` `F6` or `Esc.`


Questions asked by setup-alpine

Example setup-alpine session

The setup-alpine script offers to configure:

  • Keyboard Layout (Local keyboard language and usage mode, e.g. us and variant of us-nodeadkeys.)
  • Hostname (The name for the computer.)
  • Network (For example, automatic IP address discovery with the "DHCP" protocol.)
  • DNS Servers (Domain name servers to query. For privacy reasons it is NOT recommended to route every local request to servers like google's 8.8.8.8 .)
  • Timezone
  • Proxy (Proxy server to use for accessing the web. Use "none" for direct connections to the internet.)
  • Mirror (From where to download packages. Choose the organization to trust giving your usage patterns.)
  • SSH (Remote login server. The "openssh" is part of the default install images. Use "none" to disable remote logins, e.g. on laptops.)
  • NTP (Client package to use for keeping the system clock in sync. Package "chrony" is part of the default install images.)
  • Disk Mode (Select between diskless (disk="none"), "data" or "sys", as described above.)
 All data on the chosen device will be erased!


Rebooting and testing the new system

After the installation is completed, the system may be power-cycled or rebooted to confirm that everything is working. If the configured disk mode was "sys", the initial installation media must be removed to boot the newly installed system.

The relevant commands for this are reboot or poweroff.


Customizing the installation

The installation script only installs the base operating system. Applications such as a web server, mail server, desktop environment, or web browser are not installed and root is the only user. Please see the "Post-Install" list of links below, for some instructions on how to proceed after installation.

Further Documentation

Installing


Post-Install

Further Help and Information



Tip: Alpine linux packages stay close to the upstream design. Therefore, all upstream documentation about configuring a software package, as well as good configuration guides from other distributions that stay close to upstream, like e.g. in the Arch Wiki, are to a large degree also well applicable to configure the software on alpine linux, thus can be very useful.

Other Guides

There may still be something useful to find and sort out of the newbie's install notes in this wiki, but beware that they can contain highly opinionated content and lack explanations.

  1. Newbie_Alpine_Ecosystem
  2. Alpine newbie install manual
  3. Alpine_newbie Install section
  4. https://mckayemu.github.io/alpineinstalls/ All informatin for Spanish users