nixos-zsh-different-drives.sh

set -x

# Set a hashed root password, run mkpasswd -m SHA-512 and copy the hash here
ROOTPW=''

sgdisk --zap-all /dev/sda
sgdisk -a1 -n1:0:+100K -t1:EF02 -c 1:bootcode0 /dev/sda
sgdisk -n2:1M:+1G -t2:EF00 -c 2:efiboot0 /dev/sda
sgdisk -n3:0:+4G -t3:BE00 -c 3:nixos_zboot0 /dev/sda
sgdisk -n4:0:+2G -t4:8200 -c 4:swap0 /dev/sda
sgdisk -n5:0:+4G -t5:BF07 -c 5:log0 /dev/sda
sgdisk -n6:0:+8G -t6:BF08 -c 6:cache0 /dev/sda
sgdisk -n7:0:0 -t7:BF00 -c 7:nixos_zssd0 /dev/sda
partprobe /dev/sda
sleep 4
mkswap -L swapfs0 /dev/disk/by-partlabel/swap0
swapon /dev/disk/by-partlabel/swap0

sgdisk --zap-all /dev/sdb
sgdisk -a1 -n1:0:+100K -t1:EF02 -c 1:bootcode1 /dev/sdb
sgdisk -n2:1M:+1G -t2:EF00 -c 2:efiboot1 /dev/sdb
sgdisk -n3:0:+4G -t3:BE00 -c 3:nixos_zboot1 /dev/sdb
sgdisk -n4:0:+2G -t4:8200 -c 4:swap1 /dev/sdb
sgdisk -n5:0:+4G -t5:BF07 -c 5:log1 /dev/sdb
sgdisk -n6:0:+8G -t6:BF08 -c 6:cache1 /dev/sdb
sgdisk -n7:0:0 -t7:BF00 -c 7:nixos_zssd1 /dev/sdb
partprobe /dev/sdb
sleep 4
mkswap -L swapfs1 /dev/disk/by-partlabel/swap1
swapon /dev/disk/by-partlabel/swap1

ls -alFh --color /dev/disk/by-partlabel

zpool create -o compatibility=grub2 -o ashift=12 -o autotrim=on -O acltype=posixacl -O compression=lz4 -O devices=off -O normalization=formD -O relatime=on -O xattr=sa -O mountpoint=none -O checksum=sha256 -R /mnt zboot mirror /dev/disk/by-partlabel/nixos_zboot0 /dev/disk/by-partlabel/nixos_zboot1

zpool create -o ashift=12 -o autotrim=on -O acltype=posixacl -O compression=zstd -O dnodesize=auto -O normalization=formD -O relatime=on -O xattr=sa -O mountpoint=none -O checksum=edonr -R /mnt zssd mirror /dev/disk/by-partlabel/nixos_zssd0 /dev/disk/by-partlabel/nixos_zssd1

zpool create -o ashift=12 -o autotrim=on -O acltype=posixacl -O compression=zstd -O dnodesize=auto -O normalization=formD -O relatime=on -O xattr=sa -O mountpoint=none -O checksum=edonr -R /mnt zroot log mirror /dev/sd[ab]5 cache /dev/sd[ab]6 raidz1 /dev/sd[cdef]

zfs create zboot/nixos
zfs create -o mountpoint=/ zroot/nixos
zfs create zroot/nixos/home

zfs create zroot/nixos/keep
zfs create -o atime=off zroot/nixos/nix
zfs create zroot/nixos/root
zfs create zroot/nixos/usr
zfs create zroot/nixos/var
zfs create -o mountpoint=/boot zboot/nixos/boot

mkdir -p /mnt/mnt/tmp{1,2,3}
mkdir -p /mnt/etc/zfs/
rm -f /mnt/etc/zfs/zpool.cache
touch /mnt/etc/zfs/zpool.cache
chmod a-w /mnt/etc/zfs/zpool.cache
chattr +i /mnt/etc/zfs/zpool.cache

zfs snapshot zroot/nixos@SYSINIT
zfs snapshot zroot/nixos/usr@SYSINIT
zfs snapshot zroot/nixos/var@SYSINIT

mkfs.vfat -n EFI /dev/disk/by-partlabel/efiboot0
mkdir -p /mnt/boot/efis/efiboot0
mount -t vfat /dev/disk/by-partlabel/efiboot0 /mnt/boot/efis/efiboot0

mkfs.vfat -n EFI /dev/disk/by-partlabel/efiboot1
mkdir -p /mnt/boot/efis/efiboot1
mount -t vfat /dev/disk/by-partlabel/efiboot1 /mnt/boot/efis/efiboot1

mkdir /mnt/boot/efi
mount -t vfat /dev/disk/by-partlabel/efiboot0 /mnt/boot/efi

nixos-generate-config --root /mnt

DISK=(/dev/sda /dev/sdb)
MAINCFG="/mnt/etc/nixos/configuration.nix"
HWCFG="/mnt/etc/nixos/hardware-configuration.nix"
ZFSCFG="/mnt/etc/nixos/zfs.nix"
ZFS_BOOT="zboot"
ZFS_ROOT="zroot"
ZFS_ROOT_VOL="nixos"
EMPTYSNAP="SYSINIT"

IMPERMANENCE=1

sed -i -e "s|./hardware-configuration.nix|& ./zfs.nix|" ${MAINCFG}

if (( $IMPERMANENCE ))
then
	echo '{ config, lib, pkgs, ... }:'
else
	echo '{ config, pkgs, ... }:'
fi | tee -a ${ZFSCFG}

tee -a ${ZFSCFG} <<EOF

{
  boot.supportedFilesystems = [ "zfs" ];
  networking.hostId = "$(head -c 8 /etc/machine-id)";
  boot.kernelPackages = config.boot.zfs.package.latestCompatibleLinuxPackages;
  boot.zfs.devNodes = "/dev/disk/by-partlabel";
EOF

if (( $IMPERMANENCE ))
then
	tee -a ${ZFSCFG} <<EOF
  boot.initrd.postDeviceCommands = lib.mkAfter ''
    zfs rollback -r ${ZFS_ROOT}/${ZFS_ROOT_VOL}@${EMPTYSNAP}
  '';
EOF
fi

# Remove boot.loader stuff, it's to be added to zfs.nix
sed -i '/boot.loader/d' ${MAINCFG}

# Disable xserver. Comment them without a space after the pound sign so we can
# recognize them when we edit the config later
sed -i -e 's;^  \(services.xserver\);  #\1;' ${MAINCFG}

tee -a ${ZFSCFG} <<-'EOF'
  boot.loader.efi.efiSysMountPoint = "/boot/efi";
  boot.loader.efi.canTouchEfiVariables = false;
  boot.loader.generationsDir.copyKernels = true;
  boot.loader.grub.efiInstallAsRemovable = true;
  boot.loader.grub.enable = true;
  boot.loader.grub.version = 2;
  boot.loader.grub.copyKernels = true;
  boot.loader.grub.efiSupport = true;
  boot.loader.grub.zfsSupport = true;

  boot.loader.grub.extraPrepareConfig = ''
    mkdir -p /boot/efis
    for i in  /boot/efis/*; do mount $i ; done

    mkdir -p /boot/efi
    mount /boot/efi
  '';

  boot.loader.grub.extraInstallCommands = ''
    ESP_MIRROR=$(mktemp -d)
    cp -r /boot/efi/EFI $ESP_MIRROR
    for i in /boot/efis/*; do
      cp -r $ESP_MIRROR/EFI $i
    done
    rm -rf $ESP_MIRROR
  '';

  boot.loader.grub.devices = [
EOF

for d in ${DISK[*]}; do
  printf "    \"${d}\"\n" >>${ZFSCFG}
done

tee -a ${ZFSCFG} <<EOF
  ];

EOF

sed -i 's|fsType = "zfs";|fsType = "zfs"; options = [ "zfsutil" "X-mount.mkdir" ];|g' ${HWCFG}

ADDNR=$(awk '/^  fileSystems."\/" =$/ {print NR+3}' ${HWCFG})
sed -i "${ADDNR}i"' \      neededForBoot = true;' ${HWCFG}

ADDNR=$(awk '/^  fileSystems."\/boot" =$/ {print NR+3}' ${HWCFG})
sed -i "${ADDNR}i"' \      neededForBoot = true;' ${HWCFG}

if (( $IMPERMANENCE ))
then
	# Of course we want to keep the config files after the initial
	# reboot. So, create a bind mount from /keep/etc/nixos -> /etc/nixos
	# here, and copy the files and actually mount the bind later
	ADDNR=$(awk '/^  swapDevices =/ {print NR-1}' ${HWCFG})
	TMPFILE=$(mktemp)
	head -n ${ADDNR} ${HWCFG} > ${TMPFILE}

	tee -a ${TMPFILE} <<EOF
  fileSystems."/etc/nixos" =
    { device = "/keep/etc/nixos";
      fsType = "none";
      options = [ "bind" ];
    };

EOF

	ADDNR=$(awk '/^  swapDevices =/ {print NR}' ${HWCFG})
	tail -n +${ADDNR} ${HWCFG} >> ${TMPFILE}
	cat ${TMPFILE} > ${HWCFG}
	rm -f ${TMPFILE}
	unset ADDNR TMPFILE
fi

tee -a ${ZFSCFG} <<EOF
users.users.root.initialHashedPassword = "${ROOTPW}";

}
EOF

if (( $IMPERMANENCE ))
then
	# This is where we copy the config files and mount the bind
	install -d -m 0755 /mnt/keep/etc
	cp -a /mnt/etc/nixos /mnt/keep/etc/
	mount -o bind /mnt/keep/etc/nixos /mnt/etc/nixos
fi

set +x

echo "Now do this (preferably in another shell, this will put out a lot of text):"
echo "nixos-install -v --show-trace --no-root-passwd --root /mnt"
echo "umount -Rl /mnt"
echo "zpool export -a"
echo "swapoff -a"
echo "reboot"
echo "Make note of these instructions because the nixos-install command will output a lot of text."