mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-12-23 14:13:35 +00:00
358 lines
12 KiB
XML
358 lines
12 KiB
XML
<!-- vim: set expandtab ts=2 softtabstop=2 shiftwidth=2 smarttab textwidth=80 wrapmargin=2 -->
|
||
<section
|
||
xmlns="http://docbook.org/ns/docbook"
|
||
xmlns:xlink="http://www.w3.org/1999/xlink"
|
||
xmlns:xi="http://www.w3.org/2001/XInclude"
|
||
version="5.0"
|
||
xml:id="sec-installing-from-other-distro">
|
||
<title>Installing from another Linux distribution</title>
|
||
|
||
<para>
|
||
Because Nix (the package manager) & Nixpkgs (the Nix packages collection)
|
||
can both be installed on any (most?) Linux distributions, they can be used to
|
||
install NixOS in various creative ways. You can, for instance:
|
||
</para>
|
||
|
||
<orderedlist>
|
||
<listitem>
|
||
<para>
|
||
Install NixOS on another partition, from your existing Linux distribution
|
||
(without the use of a USB or optical device!)
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Install NixOS on the same partition (in place!), from your existing
|
||
non-NixOS Linux distribution using <literal>NIXOS_LUSTRATE</literal>.
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Install NixOS on your hard drive from the Live CD of any Linux
|
||
distribution.
|
||
</para>
|
||
</listitem>
|
||
</orderedlist>
|
||
|
||
<para>
|
||
The first steps to all these are the same:
|
||
</para>
|
||
|
||
<orderedlist>
|
||
<listitem>
|
||
<para>
|
||
Install the Nix package manager:
|
||
</para>
|
||
<para>
|
||
Short version:
|
||
</para>
|
||
<screen>
|
||
<prompt>$ </prompt>curl -L https://nixos.org/nix/install | sh
|
||
<prompt>$ </prompt>. $HOME/.nix-profile/etc/profile.d/nix.sh # …or open a fresh shell</screen>
|
||
<para>
|
||
More details in the
|
||
<link
|
||
xlink:href="https://nixos.org/nix/manual/#chap-quick-start">
|
||
Nix manual</link>
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Switch to the NixOS channel:
|
||
</para>
|
||
<para>
|
||
If you've just installed Nix on a non-NixOS distribution, you will be on
|
||
the <literal>nixpkgs</literal> channel by default.
|
||
</para>
|
||
<screen>
|
||
<prompt>$ </prompt>nix-channel --list
|
||
nixpkgs https://nixos.org/channels/nixpkgs-unstable</screen>
|
||
<para>
|
||
As that channel gets released without running the NixOS tests, it will be
|
||
safer to use the <literal>nixos-*</literal> channels instead:
|
||
</para>
|
||
<screen>
|
||
<prompt>$ </prompt>nix-channel --add https://nixos.org/channels/nixos-<replaceable>version</replaceable> nixpkgs</screen>
|
||
<para>
|
||
You may want to throw in a <literal>nix-channel --update</literal> for good
|
||
measure.
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Install the NixOS installation tools:
|
||
</para>
|
||
<para>
|
||
You'll need <literal>nixos-generate-config</literal> and
|
||
<literal>nixos-install</literal> and we'll throw in some man pages and
|
||
<literal>nixos-enter</literal> just in case you want to chroot into your
|
||
NixOS partition. They are installed by default on NixOS, but you don't have
|
||
NixOS yet..
|
||
</para>
|
||
<screen><prompt>$ </prompt>nix-env -f '<nixpkgs/nixos>' --arg configuration {} -iA config.system.build.{nixos-generate-config,nixos-install,nixos-enter,manual.manpages}</screen>
|
||
</listitem>
|
||
<listitem>
|
||
<note>
|
||
<para>
|
||
The following 5 steps are only for installing NixOS to another partition.
|
||
For installing NixOS in place using <literal>NIXOS_LUSTRATE</literal>,
|
||
skip ahead.
|
||
</para>
|
||
</note>
|
||
<para>
|
||
Prepare your target partition:
|
||
</para>
|
||
<para>
|
||
At this point it is time to prepare your target partition. Please refer to
|
||
the partitioning, file-system creation, and mounting steps of
|
||
<xref linkend="sec-installation" />
|
||
</para>
|
||
<para>
|
||
If you're about to install NixOS in place using
|
||
<literal>NIXOS_LUSTRATE</literal> there is nothing to do for this step.
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Generate your NixOS configuration:
|
||
</para>
|
||
<screen><prompt>$ </prompt>sudo `which nixos-generate-config` --root /mnt</screen>
|
||
<para>
|
||
You'll probably want to edit the configuration files. Refer to the
|
||
<literal>nixos-generate-config</literal> step in
|
||
<xref
|
||
linkend="sec-installation" /> for more
|
||
information.
|
||
</para>
|
||
<para>
|
||
Consider setting up the NixOS bootloader to give you the ability to boot on
|
||
your existing Linux partition. For instance, if you're using GRUB and your
|
||
existing distribution is running Ubuntu, you may want to add something like
|
||
this to your <literal>configuration.nix</literal>:
|
||
</para>
|
||
<programlisting>
|
||
<xref linkend="opt-boot.loader.grub.extraEntries"/> = ''
|
||
menuentry "Ubuntu" {
|
||
search --set=ubuntu --fs-uuid 3cc3e652-0c1f-4800-8451-033754f68e6e
|
||
configfile "($ubuntu)/boot/grub/grub.cfg"
|
||
}
|
||
'';</programlisting>
|
||
<para>
|
||
(You can find the appropriate UUID for your partition in
|
||
<literal>/dev/disk/by-uuid</literal>)
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Create the <literal>nixbld</literal> group and user on your original
|
||
distribution:
|
||
</para>
|
||
<screen>
|
||
<prompt>$ </prompt>sudo groupadd -g 30000 nixbld
|
||
<prompt>$ </prompt>sudo useradd -u 30000 -g nixbld -G nixbld nixbld</screen>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Download/build/install NixOS:
|
||
</para>
|
||
<warning>
|
||
<para>
|
||
Once you complete this step, you might no longer be able to boot on
|
||
existing systems without the help of a rescue USB drive or similar.
|
||
</para>
|
||
</warning>
|
||
<screen><prompt>$ </prompt>sudo PATH="$PATH" NIX_PATH="$NIX_PATH" `which nixos-install` --root /mnt</screen>
|
||
<para>
|
||
Again, please refer to the <literal>nixos-install</literal> step in
|
||
<xref linkend="sec-installation" /> for more information.
|
||
</para>
|
||
<para>
|
||
That should be it for installation to another partition!
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Optionally, you may want to clean up your non-NixOS distribution:
|
||
</para>
|
||
<screen>
|
||
<prompt>$ </prompt>sudo userdel nixbld
|
||
<prompt>$ </prompt>sudo groupdel nixbld</screen>
|
||
<para>
|
||
If you do not wish to keep the Nix package manager installed either, run
|
||
something like <literal>sudo rm -rv ~/.nix-* /nix</literal> and remove the
|
||
line that the Nix installer added to your <literal>~/.profile</literal>.
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<note>
|
||
<para>
|
||
The following steps are only for installing NixOS in place using
|
||
<literal>NIXOS_LUSTRATE</literal>:
|
||
</para>
|
||
</note>
|
||
<para>
|
||
Generate your NixOS configuration:
|
||
</para>
|
||
<screen><prompt>$ </prompt>sudo `which nixos-generate-config` --root /</screen>
|
||
<para>
|
||
Note that this will place the generated configuration files in
|
||
<literal>/etc/nixos</literal>. You'll probably want to edit the
|
||
configuration files. Refer to the <literal>nixos-generate-config</literal>
|
||
step in <xref
|
||
linkend="sec-installation" /> for more
|
||
information.
|
||
</para>
|
||
<para>
|
||
You'll likely want to set a root password for your first boot using the
|
||
configuration files because you won't have a chance to enter a password
|
||
until after you reboot. You can initalize the root password to an empty one
|
||
with this line: (and of course don't forget to set one once you've rebooted
|
||
or to lock the account with <literal>sudo passwd -l root</literal> if you
|
||
use <literal>sudo</literal>)
|
||
</para>
|
||
<programlisting>
|
||
<link linkend="opt-users.users._name_.initialHashedPassword">users.users.root.initialHashedPassword</link> = "";
|
||
</programlisting>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Build the NixOS closure and install it in the <literal>system</literal>
|
||
profile:
|
||
</para>
|
||
<screen><prompt>$ </prompt>nix-env -p /nix/var/nix/profiles/system -f '<nixpkgs/nixos>' -I nixos-config=/etc/nixos/configuration.nix -iA system</screen>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Change ownership of the <literal>/nix</literal> tree to root (since your
|
||
Nix install was probably single user):
|
||
</para>
|
||
<screen><prompt>$ </prompt>sudo chown -R 0.0 /nix</screen>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Set up the <literal>/etc/NIXOS</literal> and
|
||
<literal>/etc/NIXOS_LUSTRATE</literal> files:
|
||
</para>
|
||
<para>
|
||
<literal>/etc/NIXOS</literal> officializes that this is now a NixOS
|
||
partition (the bootup scripts require its presence).
|
||
</para>
|
||
<para>
|
||
<literal>/etc/NIXOS_LUSTRATE</literal> tells the NixOS bootup scripts to
|
||
move <emphasis>everything</emphasis> that's in the root partition to
|
||
<literal>/old-root</literal>. This will move your existing distribution out
|
||
of the way in the very early stages of the NixOS bootup. There are
|
||
exceptions (we do need to keep NixOS there after all), so the NixOS
|
||
lustrate process will not touch:
|
||
</para>
|
||
<itemizedlist>
|
||
<listitem>
|
||
<para>
|
||
The <literal>/nix</literal> directory
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
The <literal>/boot</literal> directory
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Any file or directory listed in <literal>/etc/NIXOS_LUSTRATE</literal>
|
||
(one per line)
|
||
</para>
|
||
</listitem>
|
||
</itemizedlist>
|
||
<note>
|
||
<para>
|
||
Support for <literal>NIXOS_LUSTRATE</literal> was added in NixOS 16.09.
|
||
The act of "lustrating" refers to the wiping of the existing distribution.
|
||
Creating <literal>/etc/NIXOS_LUSTRATE</literal> can also be used on NixOS
|
||
to remove all mutable files from your root partition (anything that's not
|
||
in <literal>/nix</literal> or <literal>/boot</literal> gets "lustrated" on
|
||
the next boot.
|
||
</para>
|
||
<para>
|
||
lustrate /ˈlʌstreɪt/ verb.
|
||
</para>
|
||
<para>
|
||
purify by expiatory sacrifice, ceremonial washing, or some other ritual
|
||
action.
|
||
</para>
|
||
</note>
|
||
<para>
|
||
Let's create the files:
|
||
</para>
|
||
<screen>
|
||
<prompt>$ </prompt>sudo touch /etc/NIXOS
|
||
<prompt>$ </prompt>sudo touch /etc/NIXOS_LUSTRATE
|
||
</screen>
|
||
<para>
|
||
Let's also make sure the NixOS configuration files are kept once we reboot
|
||
on NixOS:
|
||
</para>
|
||
<screen>
|
||
<prompt>$ </prompt>echo etc/nixos | sudo tee -a /etc/NIXOS_LUSTRATE
|
||
</screen>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
Finally, move the <literal>/boot</literal> directory of your current
|
||
distribution out of the way (the lustrate process will take care of the
|
||
rest once you reboot, but this one must be moved out now because NixOS
|
||
needs to install its own boot files:
|
||
</para>
|
||
<warning>
|
||
<para>
|
||
Once you complete this step, your current distribution will no longer be
|
||
bootable! If you didn't get all the NixOS configuration right, especially
|
||
those settings pertaining to boot loading and root partition, NixOS may
|
||
not be bootable either. Have a USB rescue device ready in case this
|
||
happens.
|
||
</para>
|
||
</warning>
|
||
<screen>
|
||
<prompt>$ </prompt>sudo mv -v /boot /boot.bak &&
|
||
sudo /nix/var/nix/profiles/system/bin/switch-to-configuration boot
|
||
</screen>
|
||
<para>
|
||
Cross your fingers, reboot, hopefully you should get a NixOS prompt!
|
||
</para>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
If for some reason you want to revert to the old distribution, you'll need
|
||
to boot on a USB rescue disk and do something along these lines:
|
||
</para>
|
||
<screen>
|
||
<prompt># </prompt>mkdir root
|
||
<prompt># </prompt>mount /dev/sdaX root
|
||
<prompt># </prompt>mkdir root/nixos-root
|
||
<prompt># </prompt>mv -v root/* root/nixos-root/
|
||
<prompt># </prompt>mv -v root/nixos-root/old-root/* root/
|
||
<prompt># </prompt>mv -v root/boot.bak root/boot # We had renamed this by hand earlier
|
||
<prompt># </prompt>umount root
|
||
<prompt># </prompt>reboot</screen>
|
||
<para>
|
||
This may work as is or you might also need to reinstall the boot loader
|
||
</para>
|
||
<para>
|
||
And of course, if you're happy with NixOS and no longer need the old
|
||
distribution:
|
||
</para>
|
||
<screen>sudo rm -rf /old-root</screen>
|
||
</listitem>
|
||
<listitem>
|
||
<para>
|
||
It's also worth noting that this whole process can be automated. This is
|
||
especially useful for Cloud VMs, where provider do not provide NixOS. For
|
||
instance,
|
||
<link
|
||
xlink:href="https://github.com/elitak/nixos-infect">nixos-infect</link>
|
||
uses the lustrate process to convert Digital Ocean droplets to NixOS from
|
||
other distributions automatically.
|
||
</para>
|
||
</listitem>
|
||
</orderedlist>
|
||
</section>
|