@clever i have only one device /dev/sda 
I use this 
```
diskdev=/dev/sda
bootpart=/dev/sda2
rootpart=/dev/sda3

# -o clear
# -g convert to gpt disk
# -n new partition num:start:end +size
# ef00 EFI / 8300 linux fs
sgdisk -o -g -n 1::+5M -t 1:ef02 -n 2::+500M -t 2:8300 -n 3:: -t 3:8300 $diskdev

echo "$password" | cryptsetup luksFormat --type luks1 -h sha512 $rootpart
echo "$password" | cryptsetup luksOpen $rootpart enc-pv

pvcreate /dev/mapper/enc-pv
vgcreate vg0 /dev/mapper/enc-pv
lvcreate -L 8G -n swap vg0
lvcreate -L 40G -n nixos vg0
lvcreate -l '100%FREE' -n home vg0

# format disk
mkfs.ext2 $bootpart
mkfs.ext4 -L root /dev/vg0/nixos
mkfs.ext4 -L home /dev/vg0/home
mkswap -L swap /dev/vg0/swap

swapon /dev/vg0/swap
mount /dev/vg0/nixos /mnt
mkdir /mnt/boot
mount $bootpart /mnt/boot
```
producing this :