Home Server Setup Guide (Part 3): Installing NixOS on Your Old Laptop

• A bootable USB drive (8GB+).

Choose your flavor:

• Minimal ISO (Recommended): Lightweight, terminal-only. Perfect for servers.
  🔗 Download Minimal ISO

• Graphical ISO: Includes KDE Plasma for desktop users.
  🔗 Download Graphical ISO

• Download BalenaEtcher.

• Flash the ISO to your USB drive.

Pro Tip: If your USB isn’t detected, try formatting it to FAT32 first.

• Insert the NixOS bootable USB into your laptop.

• Power on the laptop and enter the boot menu (usually by pressing F12, Esc, or Del depending on your laptop model).

• Select the USB drive and boot into the NixOS installer.

ls /sys/firmware/efi

• If the directory exists, you’re in UEFI mode (which we’ll proceed with).

• If not, you’re in Legacy mode. For Legacy mode, skip the EFI partition steps and adjust accordingly.

lsblk

• Look for a device like /dev/sda (your primary drive). If you’re unsure, double-check the size of the disk.

• Mistake I Faced : I accidentally wiped the wrong disk because I didn’t verify the disk name. Always double-check!

parted /dev/sda -- mklabel gpt

• This removes all existing partitions, so make sure you have backed up any important data.

• EFI System Partition (ESP) for boot (512MB, FAT32)

• Root partition (ext4, remaining space except swap)

• Swap partition (8GB)

# Create root partition (from 512MB to last 8GB)
parted /dev/sda -- mkpart root ext4 512MB -8GB 

# Create swap partition (last 8GB) 
parted /dev/sda -- mkpart swap linux-swap -8GB 100% 

# Create EFI partition (first 512MB) 
parted /dev/sda -- mkpart ESP fat32 1MB 512MB 
parted /dev/sda -- set 3 esp on

• Mistake I Faced: I initially created the partitions in the wrong order, which caused boot issues. Always create partitions in this order: root, swap, then EFI.

• Format Root Partition (ext4)

mkfs.ext4 -L nixos /dev/sda1

• Format Swap Partition

mkswap -L swap /dev/sda2

• Format Boot Partition (FAT32)

mkfs.fat -F 32 -n Boot /dev/sda3

• Mistake I Faced: I forgot to label the partitions, which made mounting them later a hassle. Always label your partitions!

• Mount the root partition

mount /dev/disk/by-label/nixos /mnt

• Create and mount the boot partition:

mkdir -p /mnt/boot 
mount -o umask=077 /dev/disk/by-label/Boot /mnt/boot

• Enable swap:

swapon /dev/sda2

• Mistake I Faced: I forgot to enable swap, which caused the system to run out of memory during installation. Always enable swap!

• Generate the default NixOS configuration:

nixos-generate-config --root /mnt

• Edit the configuration if needed:

nano /mnt/etc/nixos/configuration.nix

• Run the installation command:

nixos-install

• It will install NixOS based on the generated configuration. During the process, it will prompt you to set a root password:

Setting root password...
New password: *** 
Retype new password: ***

• After installation is complete, reboot:

reboot

• If you don’t have an Ethernet port (like me), you’ll need to connect to Wi-Fi via the command line. Here’s how:

ip link

• Look for an interface like wlp1s0 (your Wi-Fi adapter).

• Use iw to scan for Wi-Fi networks:

sudo iw dev wlp1s0 scan | grep SSID

• Generate a wpa_supplicant Configuration:

sudo nano /etc/wpa_supplicant.conf

• Add your Wi-Fi network details:

network={
    ssid="Your-WiFi-SSID"
    psk="Your-WiFi-Password"
}

sudo wpa_supplicant -B -i wlp1s0 -c /etc/wpa_supplicant.conf

ip link show

• Log in as root (since we haven’t created a user yet).

• you can create a user and set a password directly in the configuration.nix file. Here’s how:

sudo nano /etc/nixos/configuration.nix

users.users.yourusername = {
  isNormalUser = true;
  extraGroups = [ "wheel" ]; # Enable sudo access
  initialPassword = "yourpassword"; # Set an initial password
};

sudo nixos-rebuild switch

su - yourusername

sudo ls