* from existing install
need ~parted~ and ~btrfs-progs~
: guix shell parted btrfs-progs

* partition disk
gpt, 3 partitions:
  - 1 :: esp 2GB
  - 2 :: swap 8GB
  - 3 :: linux-fs rest

first create the partition table with ~cfdisk~, using ~gpt~ labels
: cfdisk /dev/vdb

turn on the ‘esp’ flag for partition ~1~:
: parted /dev/vdb set 1 esp on

* create filesystems
: mkfs.vfat -n ESP -F 32 /dev/vdb1

: mkfs.btrfs -L root /dev/vdb3
: mount -m -t btrfs /dev/vdb3 /mnt

: btrfs subvol create /mnt/gnu
: btrfs subvol create /mnt/gnu/store
# : btrfs subvol create /mnt/gnu/etc
: btrfs subvol create /mnt/gnu/var
: btrfs subvol create /mnt/gnu/boot
: btrfs subvol create /mnt/persist
: btrfs subvol create /mnt/persist/home
: btrfs subvol create /mnt/persist/home/root

: umount /mnt

* mount filesystems
: mount -m -t tmpfs tmpfs /mnt
: mount -m -t btrfs -o subvol=/gnu LABEL=root /mnt/gnu
# : mount -m -t btrfs -o subvol=/gnu/etc LABEL=root /mnt/etc
: mount -m -t btrfs -o subvol=/gnu/var LABEL=root /mnt/var
: mount -m -t btrfs -o subvol=/gnu/boot LABEL=root /mnt/boot
: mount -m -t btrfs -o subvol=/persist LABEL=root /mnt/persist
: mount -m -t btrfs -o subvol=/persist/home LABEL=root /mnt/home
: mount -m --bind /mnt/home/root /mnt/root
: mount -m -t vfat LABEL=ESP /mnt/boot/esp

* init system
: guix system init configuration.scm /mnt