mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-12-26 23:54:01 +00:00
458f36f5f1
So now you can write
fileSystems =
[ { mountPoint = "/";
device = "/dev/sda1";
}
];
as
fileSystems."/".device = "/dev/sda1";
341 lines
11 KiB
XML
341 lines
11 KiB
XML
<chapter xmlns="http://docbook.org/ns/docbook"
|
||
xmlns:xlink="http://www.w3.org/1999/xlink">
|
||
|
||
<title>Installation</title>
|
||
|
||
|
||
<!--===============================================================-->
|
||
|
||
<section>
|
||
|
||
<title>Obtaining NixOS</title>
|
||
|
||
<para>NixOS ISO images can be downloaded from the <link
|
||
xlink:href="http://nixos.org/nixos/download.html">NixOS
|
||
homepage</link>. These can be burned onto a CD. It is also possible
|
||
to copy them onto a USB stick and install NixOS from there. For
|
||
details, see the <link
|
||
xlink:href="https://nixos.org/wiki/Installing_NixOS_from_a_USB_stick">NixOS
|
||
Wiki</link>.</para>
|
||
|
||
</section>
|
||
|
||
|
||
<!--===============================================================-->
|
||
|
||
<section>
|
||
|
||
<title>Installation</title>
|
||
|
||
<orderedlist>
|
||
|
||
<listitem><para>Boot from the CD.</para></listitem>
|
||
|
||
<listitem><para>The CD contains a basic NixOS installation. (It
|
||
also contains Memtest86+, useful if you want to test new hardware.)
|
||
When it’s finished booting, it should have detected most of your
|
||
hardware and brought up networking (check
|
||
<command>ifconfig</command>). Networking is necessary for the
|
||
installer, since it will download lots of stuff (such as source
|
||
tarballs or Nixpkgs channel binaries). It’s best if you have a DHCP
|
||
server on your network. Otherwise configure networking manually
|
||
using <command>ifconfig</command>.</para></listitem>
|
||
|
||
<listitem><para>The NixOS manual is available on virtual console 8
|
||
(press Alt+F8 to access).</para></listitem>
|
||
|
||
<listitem><para>Login as <literal>root</literal>, empty
|
||
password.</para></listitem>
|
||
|
||
<listitem><para>If you downloaded the graphical ISO image, you can
|
||
run <command>start xserver</command> to start KDE.</para></listitem>
|
||
|
||
<listitem><para>The NixOS installer doesn’t do any partitioning or
|
||
formatting yet, so you need to that yourself. Use the following
|
||
commands:
|
||
|
||
<itemizedlist>
|
||
|
||
<listitem><para>For partitioning:
|
||
<command>fdisk</command>.</para></listitem>
|
||
|
||
<listitem><para>For initialising Ext4 partitions:
|
||
<command>mkfs.ext4</command>. It is recommended that you assign a
|
||
unique symbolic label to the file system using the option
|
||
<option>-L <replaceable>label</replaceable></option>. This will
|
||
make the file system configuration independent from device
|
||
changes.</para></listitem>
|
||
|
||
<listitem><para>For creating swap partitions:
|
||
<command>mkswap</command>. Again it’s recommended to assign a
|
||
label to the swap partition: <option>-L
|
||
<replaceable>label</replaceable></option>.</para></listitem>
|
||
|
||
<listitem><para>For creating LVM volumes, the LVM commands, e.g.,
|
||
|
||
<screen>
|
||
$ pvcreate /dev/sda1 /dev/sdb1
|
||
$ vgcreate MyVolGroup /dev/sda1 /dev/sdb1
|
||
$ lvcreate --size 2G --name bigdisk MyVolGroup
|
||
$ lvcreate --size 1G --name smalldisk MyVolGroup</screen>
|
||
|
||
</para></listitem>
|
||
|
||
<listitem><para>For creating software RAID devices, use
|
||
<command>mdadm</command>.</para></listitem>
|
||
|
||
</itemizedlist>
|
||
|
||
</para></listitem>
|
||
|
||
<listitem><para>Mount the target file system on which NixOS should
|
||
be installed on <filename>/mnt</filename>.</para></listitem>
|
||
|
||
<listitem>
|
||
|
||
<para>You now need to create a file
|
||
<filename>/mnt/etc/nixos/configuration.nix</filename> that
|
||
specifies the intended configuration of the system. This is
|
||
because NixOS has a <emphasis>declarative</emphasis> configuration
|
||
model: you create or edit a description of the configuration that
|
||
you want to be built and activated, and then NixOS takes care of
|
||
realising that configuration. The command
|
||
<command>nixos-option</command> can generate an initial
|
||
configuration file for you:
|
||
|
||
<screen>
|
||
$ nixos-option --install</screen>
|
||
|
||
It tries to figure out the kernel modules necessary for mounting
|
||
the root device, as well as various other hardware
|
||
characteristics. However, it doesn’t try to figure out the
|
||
<option>fileSystems</option> option yet.</para>
|
||
|
||
<para>You should edit
|
||
<filename>/mnt/etc/nixos/configuration.nix</filename> to suit your
|
||
needs. The text editors <command>nano</command> and
|
||
<command>vim</command> are available.</para>
|
||
|
||
<para>You need to specify a root file system in
|
||
<option>fileSystems</option> and the target device for the Grub boot
|
||
loader in <option>boot.grubDevice</option>. See
|
||
<xref linkend="ch-options"/> for a list of the available configuration
|
||
options.</para>
|
||
|
||
<note><para>It is very important that you specify in the option
|
||
<option>boot.initrd.kernelModules</option> all kernel modules that
|
||
are necessary for mounting the root file system, otherwise the
|
||
installed system will not be able to boot. (If this happens, boot
|
||
from the CD again, mount the target file system on
|
||
<filename>/mnt</filename>, fix
|
||
<filename>/mnt/etc/nixos/configuration.nix</filename> and rerun
|
||
<filename>nixos-install</filename>.) In most cases,
|
||
<command>nixos-option --install</command> will figure out the
|
||
required modules.</para></note>
|
||
|
||
<para>Examples of real-world NixOS configuration files can be
|
||
found at <link
|
||
xlink:href="https://nixos.org/repos/nix/configurations/trunk/"/>.</para>
|
||
|
||
</listitem>
|
||
|
||
<listitem><para>If your machine has a limited amount of memory, you
|
||
may want to activate swap devices now (<command>swapon
|
||
<replaceable>device</replaceable></command>). The installer (or
|
||
rather, the build actions that it may spawn) may need quite a bit of
|
||
RAM, depending on your configuration.</para></listitem>
|
||
|
||
<!--
|
||
<listitem><para>Optionally, you can run
|
||
|
||
<screen>
|
||
$ nixos-checkout</screen>
|
||
|
||
to make the installer use the latest NixOS/Nixpkgs sources from the
|
||
Subversion repository, rather than the sources on CD.</para></listitem>
|
||
-->
|
||
|
||
<listitem><para>Do the installation:
|
||
|
||
<screen>
|
||
$ nixos-install</screen>
|
||
|
||
Cross fingers.</para></listitem>
|
||
|
||
<listitem><para>If everything went well:
|
||
|
||
<screen>
|
||
$ reboot</screen>
|
||
|
||
</para></listitem>
|
||
|
||
<listitem>
|
||
|
||
<para>You should now be able to boot into the installed NixOS.
|
||
The Grub boot menu shows a list of <emphasis>available
|
||
configurations</emphasis> (initially just one). Every time you
|
||
change the NixOS configuration (see <xref
|
||
linkend="sec-changing-config" />), a new item appears in the menu.
|
||
This allows you to easily roll back to another configuration if
|
||
something goes wrong.</para>
|
||
|
||
<para>You should log in and change the <literal>root</literal>
|
||
password with <command>passwd</command>.</para>
|
||
|
||
<para>You’ll probably want to create some user accounts as well,
|
||
which can be done with <command>useradd</command>:
|
||
|
||
<screen>
|
||
$ useradd -c 'Eelco Dolstra' -m eelco
|
||
$ passwd eelco</screen>
|
||
|
||
</para>
|
||
|
||
<para>You may also want to install some software. For instance,
|
||
|
||
<screen>
|
||
$ nix-env -qa \*</screen>
|
||
|
||
shows what packages are available, and
|
||
|
||
<screen>
|
||
$ nix-env -i w3m</screen>
|
||
|
||
install the <literal>w3m</literal> browser.</para>
|
||
|
||
</listitem>
|
||
|
||
</orderedlist>
|
||
|
||
<para><xref linkend="ex-install-sequence" /> shows a typical sequence
|
||
of commands for installing NixOS on an empty hard drive (here
|
||
<filename>/dev/sda</filename>). <xref linkend="ex-config" /> shows a
|
||
corresponding configuration Nix expression.</para>
|
||
|
||
<example xml:id='ex-install-sequence'><title>Commands for installing NixOS on <filename>/dev/sda</filename></title>
|
||
<screen>
|
||
$ fdisk /dev/sda <lineannotation>(or whatever device you want to install on)</lineannotation>
|
||
$ mke2fs -j -L nixos /dev/sda1 <lineannotation>(idem)</lineannotation>
|
||
$ mkswap -L swap /dev/sda2 <lineannotation>(idem)</lineannotation>
|
||
$ mount LABEL=nixos /mnt
|
||
$ nixos-option --install
|
||
$ nano /mnt/etc/nixos/configuration.nix
|
||
<lineannotation>(in particular, set the fileSystems and swapDevices options)</lineannotation>
|
||
$ nixos-install
|
||
$ reboot</screen>
|
||
</example>
|
||
|
||
<example xml:id='ex-config'><title>NixOS configuration</title>
|
||
<screen>
|
||
{
|
||
boot.loader.grub.device = "/dev/sda";
|
||
|
||
fileSystems."/".device = "/dev/disk/by-label/nixos";
|
||
|
||
swapDevices =
|
||
[ { device = "/dev/disk/by-label/swap"; } ];
|
||
|
||
services.sshd.enable = true;
|
||
}</screen>
|
||
</example>
|
||
|
||
</section>
|
||
|
||
|
||
|
||
<!--===============================================================-->
|
||
|
||
<section xml:id="sec-changing-config">
|
||
|
||
<title>Changing the configuration</title>
|
||
|
||
<para>The file <filename>/etc/nixos/configuration.nix</filename>
|
||
contains the current configuration of your machine. Whenever you’ve
|
||
changed something to that file, you should do
|
||
|
||
<screen>
|
||
$ nixos-rebuild switch</screen>
|
||
|
||
to build the new configuration, make it the default configuration for
|
||
booting, and try to realise the configuration in the running system
|
||
(e.g., by restarting system services).</para>
|
||
|
||
<para>You can also do
|
||
|
||
<screen>
|
||
$ nixos-rebuild test</screen>
|
||
|
||
to build the configuration and switch the running system to it, but
|
||
without making it the boot default. So if (say) the configuration
|
||
locks up your machine, you can just reboot to get back to a working
|
||
configuration.</para>
|
||
|
||
<para>There is also
|
||
|
||
<screen>
|
||
$ nixos-rebuild boot</screen>
|
||
|
||
to build the configuration and make it the boot default, but not
|
||
switch to it now (so it will only take effect after the next
|
||
reboot).</para>
|
||
|
||
<para>Finally, you can do
|
||
|
||
<screen>
|
||
$ nixos-rebuild build</screen>
|
||
|
||
to build the configuration but nothing more. This is useful to see
|
||
whether everything compiles cleanly.</para>
|
||
|
||
<para>If you have a machine that supports hardware virtualisation, you
|
||
can also test the new configuration in a sandbox by building and
|
||
running a <emphasis>virtual machine</emphasis> that contains the
|
||
desired configuration. Just do
|
||
|
||
<screen>
|
||
$ nixos-rebuild build-vm
|
||
$ ./result/bin/run-*-vm
|
||
</screen>
|
||
|
||
The VM does not have use any data from your host system, so your
|
||
existing user accounts and home directories will not be
|
||
available.</para>
|
||
|
||
</section>
|
||
|
||
|
||
|
||
<!--===============================================================-->
|
||
|
||
<section>
|
||
|
||
<title>Upgrading NixOS</title>
|
||
|
||
<para>The best way to keep your NixOS installation up to date is to
|
||
use the <literal>nixos-unstable</literal> channel. (A channel is a
|
||
Nix mechanism for distributing Nix expressions and associated
|
||
binaries.) The NixOS channel is updated automatically from NixOS’s
|
||
Subversion repository after running certain tests and building most
|
||
packages.</para>
|
||
|
||
<para>NixOS automatically subscribes you to the NixOS channel. If for
|
||
some reason this is not the case, just do
|
||
|
||
<screen>
|
||
$ nix-channel --add http://nixos.org/releases/nixos/channels/nixos-unstable
|
||
</screen>
|
||
|
||
You can then upgrade NixOS to the latest version in the channel by
|
||
running
|
||
|
||
<screen>
|
||
$ nix-channel --update
|
||
</screen>
|
||
|
||
and running the <command>nixos-rebuild</command> command as described
|
||
in <xref linkend="sec-changing-config"/>.</para>
|
||
|
||
</section>
|
||
|
||
</chapter>
|