Alpine Linux - User contributions [en]

Xen Dom0

2020-08-27T08:18:20Z

Shelly:

This guide will show you how to have your 'sys' install of Alpine run as a Xen Dom0. You can start either from an existing standard install or install a new copy of Alpine with the Alpine Xen ISO.

== Install Xen ==
=== New installation ===
==== Writing the medium ====
{{Warning|This will erase '''everything''' on the drive you point it at. Check and double check that <code>/dev/sdx</code> is the correct USB device you want to write to, using the commands <code>lsblk</code> and <code>blkid</code>.}}
First download Alpine's [https://www.alpinelinux.org/downloads/ Xen install ISO], and either [[Burning ISOs|burn the ISO to a CD/DVD]] or write it to a USB storage device with the following command, where <code>3.12.0</code> should be replaced with the release number of your downloaded ISO and <code>/dev/sdx</code> should be replaced with the drive letter of your USB:
<pre>dd if=alpine-xen-3.12.0-x86_64.iso of=/dev/sdx</pre>

==== Installation ====
Now boot from your CD or USB, and type 'root' when prompted for a username. After you have logged in run <code>setup-xen-dom0</code>, then continue with a standard [[Install to disk|Alpine installation]] until you get to the prompt asking to choose your network card.
What you'll want to do is select what is to be your internet-facing interface, and when asked to bridge it type 'yes'. Then you can configure the networking settings of your bridge device, <code>br0</code>, as you would have configured your internet-facing interface.
{{Note|You cannot bridge a WiFi interface in the automatic installation script due to incompatible protocols. Make sure you pick an ethernet interface for this.}}
Now continue with your installation to disk until you reach the 'reboot' prompt. There are a few more things to do before you can boot without errors:
<pre>
# xen-hypervisor isn't installed by default with Xen so we must install it manually
apk add xen-hypervisor
apk add bridge
</pre>

Now you can safely reboot after removing your install medium, making sure to pick the <code>Alpine Linux v3.12, with Xen 4.13.1 and Linux lts</code> boot option in your GRUB menu, with 3.12 and 4.13.1 replaced with your Linux and Xen version numbers, respectively.

After this, [[Enable Community Repository|enable the Alpine community repository]] and install the firmware to be used for Xen's virtual machines:
<pre>
apk add seabios ovmf
</pre>

Now you are ready to configure GRUB.

=== Existing installation ===
First you must [[Enable Community Repository|enable the Alpine community repository]], then install Xen and the seabios (BIOS) and ovmf (UEFI) firmwares for its virtual machines.

<pre>
# apk add xen xen-hypervisor seabios ovmf
</pre>

This will install Xen Hypervisor, xl cli command and all the required packages. The next step is to modify your GRUB configuration to properly boot Xen.

The next step is to load the necessary kernel modules for Xen, we will add them to /etc/modules, so they will be loaded automatically on boot:
<pre>echo "xen-netback" >> /etc/modules
echo "xen-blkback" >> /etc/modules
echo "tun" >> /etc/modules</pre>
Then lastly we add the Xen daemons to the default runlevel.
<pre>rc-update add xenconsoled
rc-update add xendomains
rc-update add xenqemu
rc-update add xenstored</pre>
Now reboot.

== GRUB configuration ==
Once running a Xen kernel we will need to edit its command-line options and enable the setting of a default GRUB entry by inserting this at the bottom of <code>/etc/default/grub</code>:
{{Cat|/etc/default/grub|<nowiki># We need to set the amount of RAM we allocate to our Dom0 Alpine install so that
# our future virtual machines are left with enough memory.
GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=1024M,max:1024M"

GRUB_DEFAULT="saved"
GRUB_SAVEDEFAULT="true"</nowiki>}}
You can replace 1024M with the amount of memory you want to allocate to your Dom0 operating system.
After this you need to run the following:
<pre>grub-mkconfig -o /boot/grub/grub.cfg
grub-set-default "$(grep ^menuentry /boot/grub/grub.cfg | grep Xen | cut -d \' -f 2 | head -1)"
</pre>
What this does is set your default entry in GRUB to the first entry containing 'Xen'. Run this every time you upgrade Alpine or Xen.

== Loop Devices ==
If you plan to use more than 8 DomU's, you may need to increase the amount of loop-devices in your Dom0.

In Alpine Linux, you will need to add the ''max_loop'' option to the ''loop'' module, then add the loop module to your initramfs.

Start by populating <code>/etc/modprobe.d/loop.conf</code> with the module options:

<pre>
# touch /etc/modprobe.d/loop.conf
# echo "options loop max_loop=32" > /etc/modprobe.d/loop.conf
</pre>

Now reflect the module options in the initramfs:

<pre>
# mkinitfs
# reboot
</pre>

== See also ==
* [[Xen Dom0 on USB or SD]]
* [https://wiki.gentoo.org/wiki/Xen#Host_configuration_.28domain-0.29|Xen page on Gentoo wiki]
[[Category:Virtualization]]

Xen Dom0

2020-08-27T08:09:34Z

Shelly:

This guide will show you how to have your 'sys' install of Alpine run as a Xen Dom0. You can start either from an existing standard install or install a new copy of Alpine with the Alpine Xen ISO.

== Install Xen ==
=== New installation ===
==== Writing the medium ====
{{Warning|This will erase '''everything''' on the drive you point it at. Check and double check that <code>/dev/sdx</code> is the correct USB device you want to write to, using the commands <code>lsblk</code> and <code>blkid</code>.}}
First download Alpine's [https://www.alpinelinux.org/downloads/ Xen install ISO], and either [[Burning ISOs|burn the ISO to a CD/DVD]] or write it to a USB storage device with the following command, where <code>3.12.0</code> should be replaced with the release number of your downloaded ISO and <code>/dev/sdx</code> should be replaced with the drive letter of your USB:
<pre>dd if=alpine-xen-3.12.0-x86_64.iso of=/dev/sdx</pre>

==== Installation ====
Now boot from your CD or USB, and type 'root' when prompted for a username. After you have logged in run <code>setup-xen-dom0</code>, then continue with a standard [[Install to disk|Alpine installation]] until you get to the prompt asking to choose your network card.
What you'll want to do is select what is to be your internet-facing interface, and when asked to bridge it type 'yes'. Then you can configure the networking settings of your bridge device, <code>br0</code>, as you would have configured your internet-facing interface.
{{Note|You cannot bridge a WiFi interface in the automatic installation script due to incompatible protocols. Make sure you pick an ethernet interface for this.}}
Now continue with your installation to disk until you reach the 'reboot' prompt. There are a few more things to do before you can boot without errors:
<pre>
# xen-hypervisor isn't installed by default with Xen so we must install it manually
apk add xen-hypervisor
apk add bridge
</pre>

Now you can safely reboot after removing your install medium, making sure to pick the <code>Alpine Linux v3.12, with Xen 4.13.1 and Linux lts</code> boot option in your GRUB menu, with 3.12 and 4.13.1 replaced with your Linux and Xen version numbers, respectively.

After this, [[Enable Community Repository|enable the Alpine community repository]] and install the firmware to be used for Xen's virtual machines:
<pre>
apk add seabios ovmf
</pre>

Now you are ready to configure GRUB.

=== Existing installation ===
First you must [[Enable Community Repository|enable the Alpine community repository]], then install Xen and the seabios (BIOS) and ovmf (UEFI) firmwares for its virtual machines.

<pre>
# apk add xen xen-hypervisor seabios ovmf
</pre>

This will install Xen Hypervisor, xl cli command and all the required packages. The next step is to modify your GRUB configuration to properly boot Xen.

== GRUB configuration ==
Once running a Xen kernel we will need to edit its command-line options and enable the setting of a default GRUB entry by inserting this at the bottom of <code>/etc/default/grub</code>:
{{Cat|/etc/default/grub|<nowiki># We need to set the amount of RAM we allocate to our Dom0 Alpine install so that
# our future virtual machines are left with enough memory.
GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=1024M,max:1024M"

GRUB_DEFAULT="saved"
GRUB_SAVEDEFAULT="true"</nowiki>}}
You can replace 1024M with the amount of memory you want to allocate to your Dom0 operating system.
After this you need to run the following:
<pre>grub-mkconfig -o /boot/grub/grub.cfg
grub-set-default "$(grep ^menuentry /boot/grub/grub.cfg | grep Xen | cut -d \' -f 2 | head -1)"
</pre>
What this does is set your default entry in GRUB to the first entry containing 'Xen'. Run this every time you upgrade Alpine or Xen.

== Loop Devices ==
If you plan to use more than 8 DomU's, you may need to increase the amount of loop-devices in your Dom0.

In Alpine Linux, you will need to add the ''max_loop'' option to the ''loop'' module, then add the loop module to your initramfs.

Start by populating <code>/etc/modprobe.d/loop.conf</code> with the module options:

<pre>
# touch /etc/modprobe.d/loop.conf
# echo "options loop max_loop=32" > /etc/modprobe.d/loop.conf
</pre>

Now reflect the module options in the initramfs:

<pre>
# mkinitfs
# reboot
</pre>

== See also ==
* [[Xen Dom0 on USB or SD]]
* [https://wiki.gentoo.org/wiki/Xen#Host_configuration_.28domain-0.29|Xen page on Gentoo wiki]
[[Category:Virtualization]]

Xen Dom0

2020-08-27T06:18:06Z

Shelly:

This guide will show you how to have your 'sys' install of Alpine run as a Xen Dom0. You can start either from an existing standard install or install a new copy of Alpine with the Alpine Xen ISO.

== Install Xen ==
=== New installation ===
==== Writing the medium ====
{{Warning|This will erase '''everything''' on the drive you point it at. Check and double check that <code>/dev/sdx</code> is the correct USB device you want to write to, using the commands <code>lsblk</code> and <code>blkid</code>.}}
First download Alpine's [https://www.alpinelinux.org/downloads/ Xen install ISO], and either [[Burning ISOs|burn the ISO to a CD/DVD]] or write it to a USB storage device with the following command, where <code>3.12.0</code> should be replaced with the release number of your downloaded ISO and <code>/dev/sdx</code> should be replaced with the drive letter of your USB:
<pre>dd if=alpine-xen-3.12.0-x86_64.iso of=/dev/sdx</pre>

==== Installation ====
Now boot from your CD or USB, and type 'root' when prompted for a username. After you have logged in run <code>setup-xen-dom0</code>, then continue with a standard [[Install to disk|Alpine installation]] until you get to the prompt asking to choose your network card.
What you'll want to do is select what is to be your internet-facing interface, and when asked to bridge it type 'yes'. Then you can configure the networking settings of your bridge device, <code>br0</code>, as you would have configured your internet-facing interface.
{{Note|You cannot bridge a WiFi interface in the automatic installation script due to incompatible protocols. Make sure you pick an ethernet interface for this.}}
Now continue with your installation to disk until you reach the 'reboot' prompt. There are a few more things to do before you can boot without errors:
<pre>
# xen-hypervisor isn't installed by default with Xen so we must install it manually
apk add xen-hypervisor
apk add bridge
</pre>

Now you can safely reboot after removing your install medium, making sure to pick the <code>Alpine Linux v3.12, with Xen 4.13.1 and Linux lts</code> boot option in your GRUB menu, with 3.12 and 4.13.1 replaced with your Linux and Xen version numbers, respectively.

After this, [[Enable Community Repository|enable the Alpine community repository]] and install the firmware to be used for Xen's virtual machines:
<pre>
apk add seabios ovmf
</pre>

Now you are ready to configure GRUB.

=== Existing installation ===
First you must [[Enable Community Repository|enable the Alpine community repository]], then install Xen and the seabios (BIOS) and ovmf (UEFI) firmwares for its virtual machines.

<pre>
# apk add xen xen-hypervisor seabios ovmf
</pre>

This will install Xen Hypervisor, xl cli command and all the required packages. The next step is to modify your GRUB configuration to properly boot Xen.

== GRUB configuration ==
Once running a Xen kernel we will need to edit its command-line options and enable the setting of a default GRUB entry by inserting this at the bottom of <code>/etc/default/grub</code>:
{{Cat|/etc/default/grub|<nowiki># We need to set the amount of RAM we allocate to our Dom0 Alpine install so that
# our future virtual machines are left with enough memory.
GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=1024M,max:1024M"

GRUB_DEFAULT="saved"
GRUB_SAVEDEFAULT="true"</nowiki>}}
You can replace 1024M with the amount of memory you want to allocate to your Dom0 operating system.
After this you need to run the following:
<pre>grub-mkconfig -o /boot/grub/grub.cfg
grub-set-default "$(grep ^menuentry | grep Xen | cut -d \' -f 2 | head -1)"
</pre>
What this does is set your default entry in GRUB to the first entry containing 'Xen'. Run this every time you upgrade Alpine or Xen.

== Loop Devices ==
If you plan to use more than 8 DomU's, you may need to increase the amount of loop-devices in your Dom0.

In Alpine Linux, you will need to add the ''max_loop'' option to the ''loop'' module, then add the loop module to your initramfs.

Start by populating <code>/etc/modprobe.d/loop.conf</code> with the module options:

<pre>
# touch /etc/modprobe.d/loop.conf
# echo "options loop max_loop=32" > /etc/modprobe.d/loop.conf
</pre>

Now reflect the module options in the initramfs:

<pre>
# mkinitfs
# reboot
</pre>

== See also ==
* [[Xen Dom0 on USB or SD]]
* [https://wiki.gentoo.org/wiki/Xen#Host_configuration_.28domain-0.29|Xen page on Gentoo wiki]
[[Category:Virtualization]]