NixOS instructions

This document describes how to install NixOS and configure it.

Intro

• Disable the secure boot.
• Disable the RAID mode (e.g. System Configuration -> SATA Operation -> Select AHCI.).
• If you have a UEFI system, you should boot in the UEFI mode.
• Boot from your installation medium. Use the graphical installation medium, because it provides an easier interface for turning on WiFi.

Partitioning and formatting

• Use lsblk to see what devices/partitions you have.
• If you don't have devices at /dev/nvme_* you forgot to turn off the RAID mode.
• Use fdisk (BIOS) or gdisk (UEFI) to edit the partition table.

Partition	Size	Code	Purpose
1	500 MiB	EF00	EFI partition
2	remaining	8300	root file system

LUKS disk encryption

Create an encrypted root with a key you can remember:

# cryptsetup luksFormat /dev/nvme0n1p2

Then open it:

# cryptsetup luksOpen /dev/nvme0n1p2 cryptroot

File systems

Create the file system for the root partition:

# mkfs.ext4 /dev/mapper/cryptroot

Rebuild the boot partition:

# mkfs.vfat /dev/nvme0n1p1

Check the disk mapping:

$ ls -l /dev/disk/by-uuid/

Decrypted root partition will be the one that is linked to something like dm-0. You can confirm it by running:

$ ls -la /dev/mapper

Mount the decrypted cryptroot to /mnt:

# mount /dev/disk/by-uuid/<the-uuid> /mnt

Setup and mount the boot partition:

# mkdir /mnt/boot
# mount /dev/disk/by-uuid/AAAA-AAAA /mnt/boot

Initial configuration

Generate an initial configuration:

# nixos-generate-config --root /mnt

Hardware configuration should already be OK. Edit the /mnt/etc/nixos/configuration.nix as needed to create a minimal system for bootstrapping:

• Make sure that the system has git and a normal user.
• Make sure to set networking.networkmanager.enable = true, otherwise you won't have WiFi when you boot into your new system.
• Make sure to enable SDDM and Plasma (just uncomment the relevant lines in the template).

Installation

Do the installation:

# nixos-install

Enter the root password when asked. Reboot.

Setting password for the normal user

It may be necessary to first login as root and set password for the normal user with the passwd command. After that you can re-login as the normal user.

Copy your SSH and GPG keys

Now is the right time to do that. Be sure to set 600 mode for ~/.ssh/id_rsa:

$ chmod 600 ~/.ssh/id_rsa

The final rebuild

Clone this repo:

$ mkdir -p ~/projects/mrkkrp
$ cd ~/projects/mrkkrp
$ git clone git@github.com:mrkkrp/nixos-config.git nixos-config

Create a new configuration under devices by copying the previously generated /etc/nixos/configuration.nix and /etc/nixos/hardware-configuration.nix. Add a new entry in flake.nix following the existing examples.

Build the system (execute from ~/projects/mrkkrp/nixos-config):

$ nixos-rebuild --use-remote-sudo switch --flake .#<hostname>

Reboot.

Update

To update the system do:

$ nixos switch