nixos-4screen/docs/INSTALL_NIXOS_WIPE_NVME_FLAKE.md

NixOS Install Guide (wipe NVMe, install from flake on Integral300)

This guide assumes:

• You are currently on Ubuntu
• You will WIPE the entire NVMe: /dev/nvme0n1
• You will install NixOS with:
  • UEFI + systemd-boot
  • Btrfs with subvolumes (@ and @home)
  • No encryption
  • zram swap (configured in NixOS config)
• Your config repo is a flake with output: #sam-4screen-desktop
• Integral300 (ext4) is available and will be mounted on NixOS at: /data
  • UUID: 27febd74-20aa-4a3a-92c1-6fdd1ad7e88e

Important constraints:

• hosts/sam-4screen-desktop/hardware-configuration.nix is currently a placeholder. You MUST generate and copy the real one during install before running nixos-install.

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A) On Ubuntu: prepare and push the config repo to Gitea

1. Go to your repo folder (example):

   • If your repo is on Integral300 already:
     • cd /media/sam/Integral300/<your-repo-folder>
   • Otherwise clone it to Integral300:
     • cd /media/sam/Integral300
     • git clone ssh://git@<your-gitea-host>:<port>/<owner>/<repo>.git nixos-config
     • cd nixos-config

2. Ensure the flake evaluates:

   • nix --version
   • nix flake show

3. Commit your changes:

   • git status
   • git add -A
   • git commit -m "chore: prep install guide + dotfiles links"

4. Push to Gitea:

   • git push

If you don’t have flake.lock yet, you can create it:

• nix flake lock Then commit/push it too.

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B) Boot NixOS installer (ISO)

1. Boot the NixOS ISO (graphical or minimal).
2. Open a terminal.

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C) Wipe / partition / format / mount (CLI method)

WARNING: This wipes the whole NVMe. Double-check the disk is correct.

1) Identify disks

• lsblk -f Confirm:
• NVMe target: /dev/nvme0n1 (about 953G)
• Integral300 disk by UUID is present: 27febd74-20aa-4a3a-92c1-6fdd1ad7e88e

2) Wipe and create partitions

This creates:

• p1 = EFI (1GiB)
• p2 = Btrfs (rest)

Commands:

• sudo wipefs -a /dev/nvme0n1 || true

• sudo sgdisk --zap-all /dev/nvme0n1

• sudo sgdisk -n 1:1MiB:+1GiB -t 1:EF00 -c 1:EFI /dev/nvme0n1

• sudo sgdisk -n 2:0:0 -t 2:8300 -c 2:NIXOS /dev/nvme0n1

Verify:

• sudo fdisk -l /dev/nvme0n1

3) Format

• sudo mkfs.fat -F32 -n EFI /dev/nvme0n1p1
• sudo mkfs.btrfs -L nixos /dev/nvme0n1p2

4) Create Btrfs subvolumes

• sudo mount /dev/nvme0n1p2 /mnt
• sudo btrfs subvolume create /mnt/@
• sudo btrfs subvolume create /mnt/@home
• sudo umount /mnt

5) Mount target layout for install

• sudo mount -o subvol=@,compress=zstd,noatime /dev/nvme0n1p2 /mnt
• sudo mkdir -p /mnt/home
• sudo mount -o subvol=@home,compress=zstd,noatime /dev/nvme0n1p2 /mnt/home

Mount EFI at /mnt/boot (systemd-boot expects /boot):

• sudo mkdir -p /mnt/boot
• sudo mount /dev/nvme0n1p1 /mnt/boot

6) Mount Integral300 so we can access the flake repo (offline-friendly)

• sudo mkdir -p /mnt/data
• sudo mount /dev/disk/by-uuid/27febd74-20aa-4a3a-92c1-6fdd1ad7e88e /mnt/data

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D) Generate hardware-configuration.nix (REQUIRED)

1. Generate:

• sudo nixos-generate-config --root /mnt

2. Copy the generated hardware config into your repo (overwrite placeholder):

• If your repo is at /mnt/data/nixos-config:
  • sudo cp /mnt/etc/nixos/hardware-configuration.nix /mnt/data/nixos-config/hosts/sam-4screen-desktop/hardware-configuration.nix

If your repo folder name is different, adjust accordingly.

Optional sanity check:

• sed -n '1,200p' /mnt/data/nixos-config/hosts/sam-4screen-desktop/hardware-configuration.nix

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E) Install NixOS using the flake

From the installer environment, run:

• sudo nixos-install --flake /mnt/data/nixos-config#sam-4screen-desktop

Notes:

• The installer may ask you to set a root password. Do so.
• If you prefer not setting root password and using only your user + sudo, say so and we can adjust.

After install:

• sudo reboot

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F) First boot checklist (post-install)

1. Connect to Wi-Fi:

• nmtui (recommended)
• Connect to SSID: "Aussie Broadband 8729"

2. Verify static IP:

• ip a show wlp4s2 If it got DHCP, force one reconnect:
• nmcli networking off; nmcli networking on or:
• nmcli connection down "<connection name>"; nmcli connection up "<connection name>"

3. Verify SSH works (from another machine):

• ssh sam@192.168.20.27

4. Verify /data mounted:

• mount | grep ' /data '
• ls -la /data/home_sam_ubuntu/dotfiles

5. Home Manager activation:

• home-manager is integrated via NixOS switch; it should apply on rebuild.
• If dotfiles symlinks fail, confirm /data is mounted and the dotfiles paths exist.

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G) After install: commit the new hardware-configuration.nix

Back on your running system (or from Ubuntu before wiping, if you mounted and copied it there):

• cd /data/nixos-config (or wherever your repo is)
• git status
• git add hosts/sam-4screen-desktop/hardware-configuration.nix
• git commit -m "feat: add generated hardware-configuration for sam-4screen-desktop"
• git push