nixos-4screen/docs/nixos_build_spec.md

NixOS Build Spec (sam-4screen-desktop)

Disk / Boot (DO NOT BRICK WINDOWS)

Target disk: /dev/nvme0n1

• Size: 953.87 GiB (1024209543168 bytes), 2000409264 sectors
• Model: PM951 NVMe SAMSUNG 1024GB
• NVMe serial: S2FZNXAH301424
• NVMe WWID: nvme.144d-2020202020205332465a4e584148333031343234-504d393531204e564d652053414d53554e4720313032344742-00000001
• Sector size (logical/physical): 512 bytes / 512 bytes Install target is NVMe only. Do not select /dev/sdX devices in the installer.

NOTE: GPT partition table entries may not be stored/printed in on-disk (Start sector) order.

• Do NOT rely on the order shown by some tools.
• Always identify partitions by (partition number + type + UUID/label).
• If you need the physical order, sort by the “Start” sector column (e.g. fdisk -l output).

Verification commands (run before formatting):

• lsblk -o NAME,SIZE,TYPE,FSTYPE,LABEL,UUID,MOUNTPOINTS
• sudo fdisk -l /dev/nvme0n1 (interpret physical order by sorting on Start)
• sudo blkid /dev/nvme0n1p1 /dev/nvme0n1p3 /dev/nvme0n1p4 /dev/nvme0n1p5

KEEP (do not format):

• /dev/nvme0n1p1 (EFI vfat) UUID=94CC-9DA4 (~99MiB, FAT32, mounted at /boot/efi)
• /dev/nvme0n1p2 (MS reserved) (~15MiB)
• /dev/nvme0n1p3 (Windows NTFS) UUID=8294CD2994CD2111 (~503GiB)
• /dev/nvme0n1p4 (Windows recovery NTFS) UUID=6E1AA32B1AA2EEF1 (~529MiB)

WIPE + install NixOS here:

• /dev/nvme0n1p5 (currently Ubuntu ext4 /) UUID=4e99904c-ce6f-4c3c-898a-e29cfc373489 (~449GiB)

Other attached disks (DO NOT FORMAT)

• /dev/sda (240GB) model: Patriot Burst El (KEEP)
  • /dev/sda1: Microsoft reserved partition (~15MiB)
  • /dev/sda2: NTFS label "Back Up" (keep)
• /dev/sdb (500GB) ext4 label "TempBackup" (keep)
• /dev/sdc (320GB) ext4 label "Integral300" UUID=27febd74-20aa-4a3a-92c1-6fdd1ad7e88e (mount at /data)
• /dev/sde (160GB) ext4 label "XPSystemDrive" (keep)

Bootloader:

• systemd-boot, using the existing EFI partition (/dev/nvme0n1p1)

Networking

• Use NetworkManager
• Static IPv4 for wired: enp0s31f6 = 192.168.20.27/24
• Gateway: 192.168.20.1
• DNS: 192.168.20.35, 192.168.20.13

Data drive mount

• Integral300 ext4 UUID=27febd74-20aa-4a3a-92c1-6fdd1ad7e88e
• Mountpoint on NixOS: /data (preferred)

Desktop

• Primary compositor: Niri
• Display/login manager: greetd + tuigreet
• Session start command: niri --session (do not use niri-session)
• GPU: Intel HD 630 + NVIDIA Quadro P620
• Display appears to be driven by NVIDIA Quadro P620 (observed /dev/fb0 on Ubuntu scan). Treat NVIDIA as primary unless proven otherwise.

Secrets policy

• No API keys or WiFi PSKs committed to git