ROOT_DEVICE=/dev/sda2
NIXOS_BOOT=/dev/sda1

zpool create -o ashift=12 -o altroot=/mnt rpool $ROOT_DEVICE
zfs create -o mountpoint=legacy rpool/root
zfs create -o mountpoint=legacy rpool/home
zfs create -o mountpoint=legacy rpool/nix
mount -t zfs rpool/root /mnt
mkdir /mnt/{home,nix,boot}
mount -t zfs rpool/home /mnt/home
mount -t zfs rpool/nix /mnt/nix
mount $NIXOS_BOOT /mnt/boot/