NixOS installation HOWTO -- August 28, 2006

This is small HOWTO of how to build and install the current version of
NixOS.


  Building

Install Nix. Checkout nixpkgs from Subversion, as well as nixu. Adapt the
scripts in nixu to reflect the location of nixpkgs (default /nixpkgs).
Make sure mktemp is installed. Run ./make-disk.sh. Wait.

  Burning

Use your favourite tool to burn the ISO image to a CD.

  Installing

Currently NixOS can only be installed with machines that have a specific
hardware set up:

An ATA harddisk on the first ATA controller (hda) with:
- data partition
- swap partition

All data on these two partitions will be wiped and the bootloader in the
Master Boot Record (MBR) will be overwritten with GRUB.

The NixOS installer will drop you into a shell, from which you can run
fdisk. Then it expects to find a file called "disklayout" with three
variables:

SWAP :: partition to use as swap
INSTALLDEVICE :: partition that will be /root
TARGETDRIVE :: drive on which grub will be installed

This file will be read by the install script automatically when you launch
the script:

# sh fill-disk.sh

The configuration data that grub writes to disk might not be correct (should
be). When something goes wrong you probably won't have to reinstall. The
manual for grub is quite helpful in these cases.

  Configuring

To get NixOS in a working state, do the following:

- load the networkdriver. This is machine dependent. On the labmachines (Dell
Optiplex GX-260) this is the e1000 driver:

# modprobe e1000

In vmware the driver is "pcnet32".

- bring the interface up:

# ifconfig eth0 up

If the interface is different (say, eth1) replace eth0 with the right
interface.

- if DHCP is used, run a DHCP client to obtain an IP address, routing
and resolving information:

# dhclient eth0

Otherwise, do this yourself:

# ifconfig eth0 <ip address> netmask <netmask>
# route add default gw <gateway ip address>
# vim /etc/resolv.conf

  Making syslog work.

- copy /etc/services from a working Linux machine to /etc/services on the
NixOS machine (needed for sysklogd)
- copy /etc/syslog.conf from a working Linux machine to /etc/syslog.conf on the
NixOS machine (needed for sysklogd)
- launch sysklogd

  Making logins on virtual consoles work.

Logins on virtual consoles are disabled by default. To make them work:

- edit /etc/inittab and outcomment the lines with "mingetty" in them
- copy /etc/login.defs from a working Linux machine to /etc/login.defs on the
NixOS machine (needed for mingetty). Alternatively, do:

# touch /etc/login.defs

- relaunch init


  Making hotplugging work -- BROKEN RIGHT NOW

Many devices (USB, Firewire) are controlled by so called "hot plugging". The
kernel executes a program -- usually /sbin/hotplug, but this is configurable
at boottime by setting the right path in /proc/sys/kernel/hotplug -- when a
new device is added to the machine. This program makes sure the right kernel
modules are loaded and optionally, if enabled, sends a message to udev to
create the right device node in /dev (NOTE: this is not enabled in NixOS right
now).

- mount usbfs (for USB):
  # mount -t usbfs usbfs /proc/bus/usb
- install hotplug package
  - make symlinks /etc/hotplug, /etc/hotplug.d, /sbin/hotplug (TODO: make
    this pure)
  - make sure the kernel and additional modules are prepared well (currently
    this is hackish, but workable: see kernelscripts/make-kernel.sh for an
    example)
  - (optionally:) install udev
    - make a symlink to /etc/udev/udev.conf
    - launch udev
  - plug in a device