nixos install (boot + btrfs root + LUKS setup)

btrfs-nixos-install.sh

mkfs.vfat -n BOOT /dev/sda3
mkfs.btrfs -L root /dev/sda1

cryptsetup luksFormat /dev/sda1

# Enter the Password.

cryptsetup luksOpen /dev/sda1 enc-pv

# After Opening the Disk, Open Gparted and Format /dev/sda1 to btrfs for the btrfs logic block.
# Add a label to /dev/sda1 too as nixos

mount -t btrfs /dev/disk/by-label/nixos /mnt/
btrfs subvolume create /mnt/nixos
umount /mnt/
mount -t btrfs -o subvol=nixos /dev/disk/by-label/nixos /mnt/
btrfs subvolume create /mnt/var
btrfs subvolume create /mnt/home
btrfs subvolume create /mnt/tmp

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

nixos-generate-config --root /mnt/

# edit the config; see
# https://nixos.org/nixos/manual/index.html#sec-installation
vim /mnt/etc/nixos/configuration.nix
nixos-install
reboot