diff --git a/default.nix b/default.nix
index 3265f02..6476340 100644
--- a/default.nix
+++ b/default.nix
@@ -2,7 +2,7 @@
 , rootMountPoint ? "/mnt"
 }:
 let
-  types = import ./types.nix { inherit lib rootMountPoint; };
+  types = import ./types { inherit lib rootMountPoint; };
   eval = cfg: lib.evalModules {
     modules = lib.singleton {
       # _file = toString input;
diff --git a/doc.nix b/doc.nix
index be556ab..2c427ec 100644
--- a/doc.nix
+++ b/doc.nix
@@ -1,7 +1,7 @@
 { lib, nixosOptionsDoc, runCommand, fetchurl, pandoc }:
 
 let
-  types = import ./types.nix {
+  types = import ./types {
     inherit lib;
     rootMountPoint = "/mnt";
   };
diff --git a/module.nix b/module.nix
index 66a828e..49afeb5 100644
--- a/module.nix
+++ b/module.nix
@@ -1,6 +1,6 @@
 { config, lib, pkgs, ... }:
 let
-  types = import ./types.nix {
+  types = import ./types {
     inherit lib;
     rootMountPoint = config.disko.rootMountPoint;
   };
diff --git a/types/btrfs.nix b/types/btrfs.nix
new file mode 100644
index 0000000..a91f822
--- /dev/null
+++ b/types/btrfs.nix
@@ -0,0 +1,86 @@
+({ config, options, diskoLib, lib, subTypes, optionTypes, rootMountPoint, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "btrfs" ];
+      internal = true;
+      description = "Type";
+    };
+    extraArgs = lib.mkOption {
+      type = lib.types.str;
+      default = "";
+      description = "Arguments to pass to BTRFS";
+    };
+    mountOptions = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ "defaults" ];
+      description = "A list of options to pass to mount.";
+    };
+    subvolumes = lib.mkOption {
+      type = lib.types.attrsOf subTypes.btrfs_subvol;
+      default = { };
+      description = "Subvolumes to define for BTRFS.";
+    };
+    mountpoint = lib.mkOption {
+      type = lib.types.nullOr optionTypes.absolute-pathname;
+      default = null;
+      description = "A path to mount the BTRFS filesystem to.";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev:
+        diskoLib.deepMergeMap (subvol: subvol._meta dev) (lib.attrValues config.subvolumes);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        mkfs.btrfs ${dev} ${config.extraArgs}
+        ${lib.concatMapStrings (subvol: subvol._create { inherit dev; }) (lib.attrValues config.subvolumes)}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }:
+        let
+          subvolMounts = diskoLib.deepMergeMap (subvol: subvol._mount { inherit dev; parent = config.mountpoint; }) (lib.attrValues config.subvolumes);
+        in
+        {
+          fs = subvolMounts.fs // lib.optionalAttrs (!isNull config.mountpoint) {
+            ${config.mountpoint} = ''
+              if ! findmnt ${dev} "${rootMountPoint}${config.mountpoint}" > /dev/null 2>&1; then
+                mount ${dev} "${rootMountPoint}${config.mountpoint}" \
+                ${lib.concatMapStringsSep " " (opt: "-o ${opt}") config.mountOptions} \
+                -o X-mount.mkdir
+              fi
+            '';
+          };
+        };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev: [
+        (map (subvol: subvol._config dev config.mountpoint) (lib.attrValues config.subvolumes))
+        (lib.optional (!isNull config.mountpoint) {
+          fileSystems.${config.mountpoint} = {
+            device = dev;
+            fsType = "btrfs";
+            options = config.mountOptions;
+          };
+        })
+      ];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs:
+        [ pkgs.btrfs-progs ] ++ lib.flatten (map (subvolume: subvolume._pkgs pkgs) (lib.attrValues config.subvolumes));
+      description = "Packages";
+    };
+  };
+})
diff --git a/types/btrfs_subvol.nix b/types/btrfs_subvol.nix
new file mode 100644
index 0000000..c3223d1
--- /dev/null
+++ b/types/btrfs_subvol.nix
@@ -0,0 +1,94 @@
+{ config, options, diskoLib, lib, optionTypes, rootMountPoint, ... }:
+{
+  options = {
+    name = lib.mkOption {
+      type = lib.types.str;
+      default = config._module.args.name;
+      description = "Name of the BTRFS subvolume.";
+    };
+    type = lib.mkOption {
+      type = lib.types.enum [ "btrfs_subvol" ];
+      default = "btrfs_subvol";
+      internal = true;
+      description = "Type";
+    };
+    extraArgs = lib.mkOption {
+      type = lib.types.str;
+      default = "";
+      description = "Extra arguments to pass";
+    };
+    mountOptions = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ "defaults" ];
+      description = "Options to pass to mount";
+    };
+    mountpoint = lib.mkOption {
+      type = lib.types.nullOr optionTypes.absolute-pathname;
+      default = null;
+      description = "Location to mount the subvolume to.";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev: { };
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        MNTPOINT=$(mktemp -d)
+        (
+          mount ${dev} "$MNTPOINT" -o subvol=/
+          trap 'umount $MNTPOINT; rm -rf $MNTPOINT' EXIT
+          btrfs subvolume create "$MNTPOINT"/${config.name} ${config.extraArgs}
+        )
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev, parent }:
+        let
+          mountpoint =
+            if (!isNull config.mountpoint) then config.mountpoint
+            else if (isNull parent) then config.name
+            else null;
+        in
+        lib.optionalAttrs (!isNull mountpoint) {
+          fs.${mountpoint} = ''
+            if ! findmnt ${dev} "${rootMountPoint}${mountpoint}" > /dev/null 2>&1; then
+              mount ${dev} "${rootMountPoint}${mountpoint}" \
+              ${lib.concatMapStringsSep " " (opt: "-o ${opt}") (config.mountOptions ++ [ "subvol=${config.name}" ])} \
+              -o X-mount.mkdir
+            fi
+          '';
+        };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev: parent:
+        let
+          mountpoint =
+            if (!isNull config.mountpoint) then config.mountpoint
+            else if (isNull parent) then config.name
+            else null;
+        in
+        lib.optional (!isNull mountpoint) {
+          fileSystems.${mountpoint} = {
+            device = dev;
+            fsType = "btrfs";
+            options = config.mountOptions ++ [ "subvol=${config.name}" ];
+          };
+        };
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.coreutils ];
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/default.nix b/types/default.nix
new file mode 100644
index 0000000..96c7dfa
--- /dev/null
+++ b/types/default.nix
@@ -0,0 +1,346 @@
+{ lib, rootMountPoint }:
+with lib;
+with builtins;
+
+rec {
+
+  diskoLib = {
+    # like lib.types.oneOf but instead of a list takes an attrset
+    # uses the field "type" to find the correct type in the attrset
+    subType = typeAttr: lib.mkOptionType rec {
+      name = "subType";
+      description = "one of ${concatStringsSep "," (attrNames typeAttr)}";
+      check = x: if x ? type then typeAttr.${x.type}.check x else throw "No type option set in:\n${generators.toPretty {} x}";
+      merge = loc: defs:
+        foldl' (res: def: typeAttr.${def.value.type}.merge loc [ def ]) { } defs;
+      nestedTypes = typeAttr;
+    };
+
+    # option for valid contents of partitions (basically like devices, but without tables)
+    partitionType = lib.mkOption {
+      type = lib.types.nullOr (diskoLib.subType { inherit (subTypes) btrfs filesystem zfs mdraid luks lvm_pv swap; });
+      default = null;
+      description = "The type of partition";
+    };
+
+    # option for valid contents of devices
+    deviceType = lib.mkOption {
+      type = lib.types.nullOr (diskoLib.subType { inherit (subTypes) table btrfs filesystem zfs mdraid luks lvm_pv swap; });
+      default = null;
+      description = "The type of device";
+    };
+
+    /* deepMergeMap takes a function and a list of attrsets and deep merges them
+
+       deepMergeMap :: -> (AttrSet -> AttrSet ) -> [ AttrSet ] -> Attrset
+
+       Example:
+         deepMergeMap (x: x.t = "test") [ { x = { y = 1; z = 3; }; } { x = { bla = 234; }; } ]
+         => { x = { y = 1; z = 3; bla = 234; t = "test"; }; }
+    */
+    deepMergeMap = f: listOfAttrs:
+      foldr (attr: acc: (recursiveUpdate acc (f attr))) { } listOfAttrs;
+
+    /* get a device and an index to get the matching device name
+
+       deviceNumbering :: str -> int -> str
+
+       Example:
+       deviceNumbering "/dev/sda" 3
+       => "/dev/sda3"
+
+       deviceNumbering "/dev/disk/by-id/xxx" 2
+       => "/dev/disk/by-id/xxx-part2"
+    */
+    deviceNumbering = dev: index:
+      if match "/dev/[vs]d.+" dev != null then
+        dev + toString index  # /dev/{s,v}da style
+      else if match "/dev/disk/.+" dev != null then
+        "${dev}-part${toString index}" # /dev/disk/by-id/xxx style
+      else if match "/dev/(nvme|md/|mmcblk).+" dev != null then
+        "${dev}p${toString index}" # /dev/nvme0n1p1 style
+      else
+        abort "${dev} seems not to be a supported disk format";
+
+    /* A nix option type representing a json datastructure, vendored from nixpkgs to avoid dependency on pkgs */
+    jsonType =
+      let
+        valueType = lib.types.nullOr
+          (lib.types.oneOf [
+            lib.types.bool
+            lib.types.int
+            lib.types.float
+            lib.types.str
+            lib.types.path
+            (lib.types.attrsOf valueType)
+            (lib.types.listOf valueType)
+          ]) // {
+          description = "JSON value";
+        };
+      in
+      valueType;
+
+    /* Given a attrset of deviceDependencies and a devices attrset
+       returns a sorted list by deviceDependencies. aborts if a loop is found
+
+       sortDevicesByDependencies :: AttrSet -> AttrSet -> [ [ str str ] ]
+    */
+    sortDevicesByDependencies = deviceDependencies: devices:
+      let
+        dependsOn = a: b:
+          elem a (attrByPath b [ ] deviceDependencies);
+        maybeSortedDevices = toposort dependsOn (diskoLib.deviceList devices);
+      in
+      if (hasAttr "cycle" maybeSortedDevices) then
+        abort "detected a cycle in your disk setup: ${maybeSortedDevices.cycle}"
+      else
+        maybeSortedDevices.result;
+
+    /* Takes a devices attrSet and returns it as a list
+
+       deviceList :: AttrSet -> [ [ str str ] ]
+
+       Example:
+         deviceList { zfs.pool1 = {}; zfs.pool2 = {}; mdadm.raid1 = {}; }
+         => [ [ "zfs" "pool1" ] [ "zfs" "pool2" ] [ "mdadm" "raid1" ] ]
+    */
+    deviceList = devices:
+      concatLists (mapAttrsToList (n: v: (map (x: [ n x ]) (attrNames v))) devices);
+
+    /* Takes either a string or null and returns the string or an empty string
+
+       maybeStr :: Either (str null) -> str
+
+       Example:
+         maybeStr null
+         => ""
+         maybeSTr "hello world"
+         => "hello world"
+    */
+    maybeStr = x: optionalString (!isNull x) x;
+
+    /* Takes a Submodules config and options argument and returns a serializable
+       subset of config variables as a shell script snippet.
+    */
+    defineHookVariables = { config, options }:
+      let
+        sanitizeName = lib.replaceStrings [ "-" ] [ "_" ];
+        isAttrsOfSubmodule = o: o.type.name == "attrsOf" && o.type.nestedTypes.elemType.name == "submodule";
+        isSerializable = n: o: !(
+          lib.hasPrefix "_" n
+          || lib.hasSuffix "Hook" n
+          || isAttrsOfSubmodule o
+          # TODO don't hardcode diskoLib.subType options.
+          || n == "content" || n == "partitions"
+        );
+      in
+      lib.toShellVars
+        (lib.mapAttrs'
+          (n: o: lib.nameValuePair (sanitizeName n) o.value)
+          (lib.filterAttrs isSerializable options));
+
+    mkHook = description: lib.mkOption {
+      inherit description;
+      type = lib.types.str;
+      default = "";
+    };
+
+    mkSubType = module: lib.types.submodule ([
+      module
+
+      {
+        options = {
+          preCreateHook = diskoLib.mkHook "shell commands to run before create";
+          postCreateHook = diskoLib.mkHook "shell commands to run after create";
+          preMountHook = diskoLib.mkHook "shell commands to run before mount";
+          postMountHook = diskoLib.mkHook "shell commands to run after mount";
+        };
+        config._module.args = {
+          inherit diskoLib optionTypes subTypes rootMountPoint;
+        };
+      }
+    ]);
+
+    mkCreateOption = { config, options, default }@attrs:
+      lib.mkOption {
+        internal = true;
+        readOnly = true;
+        type = lib.types.functionTo lib.types.str;
+        default = args:
+          let
+            name = "format";
+            test = lib.optionalString (config ? name) "${config.${name}}";
+          in
+          ''
+            ( # ${config.type} ${concatMapStringsSep " " (n: toString (config.${n} or "")) ["name" "device" "format" "mountpoint"]}
+              ${diskoLib.defineHookVariables { inherit config options; }}
+              ${config.preCreateHook}
+              ${attrs.default args}
+              ${config.postCreateHook}
+            )
+          '';
+        description = "Creation script";
+      };
+
+    mkMountOption = { config, options, default }@attrs:
+      lib.mkOption {
+        internal = true;
+        readOnly = true;
+        type = lib.types.functionTo diskoLib.jsonType;
+        default = args: attrs.default args;
+        description = "Mount script";
+      };
+
+
+    /* Takes a disko device specification, returns an attrset with metadata
+
+       meta :: lib.types.devices -> AttrSet
+    */
+    meta = devices: diskoLib.deepMergeMap (dev: dev._meta) (flatten (map attrValues (attrValues devices)));
+
+    /* Takes a disko device specification and returns a string which formats the disks
+
+       create :: lib.types.devices -> str
+    */
+    create = devices:
+      let
+        sortedDeviceList = diskoLib.sortDevicesByDependencies ((diskoLib.meta devices).deviceDependencies or { }) devices;
+      in
+      ''
+        set -efux
+
+        disko_devices_dir=$(mktemp -d)
+        trap 'rm -rf "$disko_devices_dir"' EXIT
+        mkdir -p "$disko_devices_dir"
+
+        ${concatMapStrings (dev: (attrByPath (dev ++ [ "_create" ]) ({}: {}) devices) {}) sortedDeviceList}
+      '';
+    /* Takes a disko device specification and returns a string which mounts the disks
+
+       mount :: lib.types.devices -> str
+    */
+    mount = devices:
+      let
+        fsMounts = diskoLib.deepMergeMap (dev: (dev._mount { }).fs or { }) (flatten (map attrValues (attrValues devices)));
+        sortedDeviceList = diskoLib.sortDevicesByDependencies ((diskoLib.meta devices).deviceDependencies or { }) devices;
+      in
+      ''
+        set -efux
+        # first create the necessary devices
+        ${concatMapStrings (dev: ((attrByPath (dev ++ [ "_mount" ]) {} devices) {}).dev or "") sortedDeviceList}
+
+        # and then mount the filesystems in alphabetical order
+        ${concatStrings (attrValues fsMounts)}
+      '';
+
+    /* takes a disko device specification and returns a string which unmounts, destroys all disks and then runs create and mount
+
+       zapCreateMount :: lib.types.devices -> str
+    */
+    zapCreateMount = devices: ''
+      set -efux
+      umount -Rv "${rootMountPoint}" || :
+
+      for dev in ${toString (lib.catAttrs "device" (lib.attrValues devices.disk))}; do
+        ${../disk-deactivate}/disk-deactivate "$dev" | bash -x
+      done
+
+      echo 'creating partitions...'
+      ${diskoLib.create devices}
+      echo 'mounting partitions...'
+      ${diskoLib.mount devices}
+    '';
+    /* Takes a disko device specification and returns a nixos configuration
+
+       config :: lib.types.devices -> nixosConfig
+    */
+    config = devices: flatten (map (dev: dev._config) (flatten (map attrValues (attrValues devices))));
+    /* Takes a disko device specification and returns a function to get the needed packages to format/mount the disks
+
+       packages :: lib.types.devices -> pkgs -> [ derivation ]
+    */
+    packages = devices: pkgs: unique (flatten (map (dev: dev._pkgs pkgs) (flatten (map attrValues (attrValues devices)))));
+  };
+
+  optionTypes = rec {
+    filename = lib.mkOptionType {
+      name = "filename";
+      check = isString;
+      merge = mergeOneOption;
+      description = "A filename";
+    };
+
+    absolute-pathname = lib.mkOptionType {
+      name = "absolute pathname";
+      check = x: isString x && substring 0 1 x == "/" && pathname.check x;
+      merge = mergeOneOption;
+      description = "An absolute path";
+    };
+
+    pathname = lib.mkOptionType {
+      name = "pathname";
+      check = x:
+        let
+          # The filter is used to normalize paths, i.e. to remove duplicated and
+          # trailing slashes.  It also removes leading slashes, thus we have to
+          # check for "/" explicitly below.
+          xs = filter (s: stringLength s > 0) (splitString "/" x);
+        in
+        isString x && (x == "/" || (length xs > 0 && all filename.check xs));
+      merge = mergeOneOption;
+      description = "A path name";
+    };
+  };
+
+  /* topLevel type of the disko config, takes attrsets of disks, mdadms, zpools, nodevs, and lvm vgs.
+  */
+  devices = lib.types.submodule {
+    options = {
+      disk = lib.mkOption {
+        type = lib.types.attrsOf subTypes.disk;
+        default = { };
+        description = "Block device";
+      };
+      mdadm = lib.mkOption {
+        type = lib.types.attrsOf subTypes.mdadm;
+        default = { };
+        description = "mdadm device";
+      };
+      zpool = lib.mkOption {
+        type = lib.types.attrsOf subTypes.zpool;
+        default = { };
+        description = "ZFS pool device";
+      };
+      lvm_vg = lib.mkOption {
+        type = lib.types.attrsOf subTypes.lvm_vg;
+        default = { };
+        description = "LVM VG device";
+      };
+      nodev = lib.mkOption {
+        type = lib.types.attrsOf subTypes.nodev;
+        default = { };
+        description = "A non-block device";
+      };
+    };
+  };
+
+  subTypes = lib.mapAttrs (_: module: diskoLib.mkSubType module) {
+    nodev =  ./nodev.nix;
+    btrfs = ./btrfs.nix;
+    btrfs_subvol = ./btrfs_subvol.nix;
+    filesystem = ./filesystem.nix;
+    table = ./table.nix;
+    partition = ./partition.nix;
+    swap = ./swap.nix;
+    lvm_pv = ./lvm_pv.nix;
+    lvm_vg = ./lvm_vg.nix;
+    lvm_lv = ./lvm_lv.nix;
+    zfs = ./zfs.nix;
+    zpool = ./zpool.nix;
+    zfs_dataset = ./zfs_dataset.nix;
+    mdadm = ./mdadm.nix;
+    mdraid = ./mdraid.nix;
+    luks = ./luks.nix;
+    disk =  ./disk.nix;
+  };
+}
diff --git a/types/disk.nix b/types/disk.nix
new file mode 100644
index 0000000..ab59de9
--- /dev/null
+++ b/types/disk.nix
@@ -0,0 +1,52 @@
+{ config, options, lib, diskoLib, optionTypes, ... }:
+{
+  options = {
+    name = lib.mkOption {
+      type = lib.types.str;
+      default = config._module.args.name;
+      description = "Device name";
+    };
+    type = lib.mkOption {
+      type = lib.types.enum [ "disk" ];
+      default = "disk";
+      internal = true;
+      description = "Type";
+    };
+    device = lib.mkOption {
+      type = optionTypes.absolute-pathname; # TODO check if subpath of /dev ? - No! eg: /.swapfile
+      description = "Device path";
+    };
+    content = diskoLib.deviceType;
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = diskoLib.jsonType;
+      default =
+        lib.optionalAttrs (!isNull config.content) (config.content._meta [ "disk" config.device ]);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = {}: config.content._create { dev = config.device; };
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = {}:
+        lib.optionalAttrs (!isNull config.content) (config.content._mount { dev = config.device; });
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default =
+        lib.optional (!isNull config.content) (config.content._config config.device);
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.jq ] ++ lib.optionals (!isNull config.content) (config.content._pkgs pkgs);
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/filesystem.nix b/types/filesystem.nix
new file mode 100644
index 0000000..c9a3319
--- /dev/null
+++ b/types/filesystem.nix
@@ -0,0 +1,86 @@
+{ config, options, lib, diskoLib, optionTypes, rootMountPoint, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "filesystem" ];
+      internal = true;
+      description = "Type";
+    };
+    extraArgs = lib.mkOption {
+      type = lib.types.str;
+      default = "";
+      description = "Arguments to pass";
+    };
+    mountOptions = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ "defaults" ];
+      description = "Options to pass to mount";
+    };
+    mountpoint = lib.mkOption {
+      type = optionTypes.absolute-pathname;
+      description = "Path to mount the filesystem to";
+    };
+    format = lib.mkOption {
+      type = lib.types.str;
+      description = "Format of the filesystem";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev: { };
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        mkfs.${config.format} \
+          ${config.extraArgs} \
+          ${dev}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }: {
+        fs.${config.mountpoint} = ''
+          if ! findmnt ${dev} "${rootMountPoint}${config.mountpoint}" > /dev/null 2>&1; then
+            mount ${dev} "${rootMountPoint}${config.mountpoint}" \
+              -t "${config.format}" \
+              ${lib.concatMapStringsSep " " (opt: "-o ${opt}") config.mountOptions} \
+              -o X-mount.mkdir
+          fi
+        '';
+      };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev: [{
+        fileSystems.${config.mountpoint} = {
+          device = dev;
+          fsType = config.format;
+          options = config.mountOptions;
+        };
+      }];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      # type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs:
+        [ pkgs.util-linux ] ++ (
+          # TODO add many more
+          if (config.format == "xfs") then [ pkgs.xfsprogs ]
+          else if (config.format == "btrfs") then [ pkgs.btrfs-progs ]
+          else if (config.format == "vfat") then [ pkgs.dosfstools ]
+          else if (config.format == "ext2") then [ pkgs.e2fsprogs ]
+          else if (config.format == "ext3") then [ pkgs.e2fsprogs ]
+          else if (config.format == "ext4") then [ pkgs.e2fsprogs ]
+          else if (config.format == "bcachefs") then [ pkgs.bcachefs-tools ]
+          else [ ]
+        );
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/luks.nix b/types/luks.nix
new file mode 100644
index 0000000..07d685f
--- /dev/null
+++ b/types/luks.nix
@@ -0,0 +1,73 @@
+{ config, options, lib, diskoLib, optionTypes, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "luks" ];
+      internal = true;
+      description = "Type";
+    };
+    name = lib.mkOption {
+      type = lib.types.str;
+      description = "Name of the LUKS";
+    };
+    keyFile = lib.mkOption {
+      type = lib.types.nullOr optionTypes.absolute-pathname;
+      default = null;
+      description = "Path to the key for encryption";
+    };
+    extraArgs = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ ];
+      description = "Extra arguments";
+    };
+    content = diskoLib.deviceType;
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev:
+        lib.optionalAttrs (!isNull config.content) (config.content._meta dev);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        cryptsetup -q luksFormat ${dev} ${diskoLib.maybeStr config.keyFile} ${toString config.extraArgs}
+        cryptsetup luksOpen ${dev} ${config.name} ${lib.optionalString (!isNull config.keyFile) "--key-file ${config.keyFile}"}
+        ${lib.optionalString (!isNull config.content) (config.content._create {dev = "/dev/mapper/${config.name}";})}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }:
+        let
+          contentMount = config.content._mount { dev = "/dev/mapper/${config.name}"; };
+        in
+        {
+          dev = ''
+            cryptsetup status ${config.name} >/dev/null 2>/dev/null ||
+              cryptsetup luksOpen ${dev} ${config.name} ${lib.optionalString (!isNull config.keyFile) "--key-file ${config.keyFile}"}
+            ${lib.optionalString (!isNull config.content) contentMount.dev or ""}
+          '';
+          fs = lib.optionalAttrs (!isNull config.content) contentMount.fs or { };
+        };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev:
+        [
+          # TODO do we need this always in initrd and only there?
+          { boot.initrd.luks.devices.${config.name}.device = dev; }
+        ] ++ (lib.optional (!isNull config.content) (config.content._config "/dev/mapper/${config.name}"));
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.cryptsetup ] ++ (lib.optionals (!isNull config.content) (config.content._pkgs pkgs));
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/lvm_lv.nix b/types/lvm_lv.nix
new file mode 100644
index 0000000..6b1328b
--- /dev/null
+++ b/types/lvm_lv.nix
@@ -0,0 +1,76 @@
+{ config, options, lib, diskoLib, ... }:
+{
+  options = {
+    name = lib.mkOption {
+      type = lib.types.str;
+      default = config._module.args.name;
+      description = "Name of the logical volume";
+    };
+    type = lib.mkOption {
+      type = lib.types.enum [ "lvm_lv" ];
+      default = "lvm_lv";
+      internal = true;
+      description = "Type";
+    };
+    size = lib.mkOption {
+      type = lib.types.str; # TODO lvm size type
+      description = "Size of the logical volume";
+    };
+    lvm_type = lib.mkOption {
+      type = lib.types.nullOr (lib.types.enum [ "mirror" "raid0" "raid1" ]); # TODO add all lib.types
+      default = null; # maybe there is always a default type?
+      description = "LVM type";
+    };
+    extraArgs = lib.mkOption {
+      type = lib.types.str;
+      default = "";
+      description = "Extra arguments";
+    };
+    content = diskoLib.partitionType;
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev:
+        lib.optionalAttrs (!isNull config.content) (config.content._meta dev);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { vg }: ''
+        lvcreate \
+          --yes \
+          ${if lib.hasInfix "%" config.size then "-l" else "-L"} ${config.size} \
+          -n ${config.name} \
+          ${lib.optionalString (!isNull config.lvm_type) "--type=${config.lvm_type}"} \
+          ${config.extraArgs} \
+          ${vg}
+        ${lib.optionalString (!isNull config.content) (config.content._create {dev = "/dev/${vg}/${config.name}";})}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { vg }:
+        lib.optionalAttrs (!isNull config.content) (config.content._mount { dev = "/dev/${vg}/${config.name}"; });
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = vg:
+        [
+          (lib.optional (!isNull config.content) (config.content._config "/dev/${vg}/${config.name}"))
+          (lib.optional (!isNull config.lvm_type) {
+            boot.initrd.kernelModules = [ "dm-${config.lvm_type}" ];
+          })
+        ];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: lib.optionals (!isNull config.content) (config.content._pkgs pkgs);
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/lvm_pv.nix b/types/lvm_pv.nix
new file mode 100644
index 0000000..03a95c7
--- /dev/null
+++ b/types/lvm_pv.nix
@@ -0,0 +1,48 @@
+{ config, options, lib, diskoLib, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "lvm_pv" ];
+      internal = true;
+      description = "Type";
+    };
+    vg = lib.mkOption {
+      type = lib.types.str;
+      description = "Volume group";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev: {
+        deviceDependencies.lvm_vg.${config.vg} = [ dev ];
+      };
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        pvcreate ${dev}
+        echo "${dev}" >> $disko_devices_dir/lvm_${config.vg}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }:
+        { };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev: [ ];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.lvm2 ];
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/lvm_vg.nix b/types/lvm_vg.nix
new file mode 100644
index 0000000..786fbd7
--- /dev/null
+++ b/types/lvm_vg.nix
@@ -0,0 +1,63 @@
+{ config, options, lib, diskoLib, subTypes, ... }:
+{
+  options = {
+    name = lib.mkOption {
+      type = lib.types.str;
+      default = config._module.args.name;
+      description = "Name of the volume gorup";
+    };
+    type = lib.mkOption {
+      type = lib.types.enum [ "lvm_vg" ];
+      internal = true;
+      description = "Type";
+    };
+    lvs = lib.mkOption {
+      type = lib.types.attrsOf subTypes.lvm_lv;
+      default = { };
+      description = "LVS for the volume group";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = diskoLib.jsonType;
+      default =
+        diskoLib.deepMergeMap (lv: lv._meta [ "lvm_vg" config.name ]) (lib.attrValues config.lvs);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = {}: ''
+        vgcreate ${config.name} $(tr '\n' ' ' < $disko_devices_dir/lvm_${config.name})
+        ${lib.concatMapStrings (lv: lv._create {vg = config.name; }) (lib.attrValues config.lvs)}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = {}:
+        let
+          lvMounts = diskoLib.deepMergeMap (lv: lv._mount { vg = config.name; }) (lib.attrValues config.lvs);
+        in
+        {
+          dev = ''
+            vgchange -a y
+            ${lib.concatMapStrings (x: x.dev or "") (lib.attrValues lvMounts)}
+          '';
+          fs = lvMounts.fs;
+        };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default =
+        map (lv: lv._config config.name) (lib.attrValues config.lvs);
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: lib.flatten (map (lv: lv._pkgs pkgs) (lib.attrValues config.lvs));
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/mdadm.nix b/types/mdadm.nix
new file mode 100644
index 0000000..d2e88d0
--- /dev/null
+++ b/types/mdadm.nix
@@ -0,0 +1,69 @@
+{ config, options, lib, diskoLib, ... }:
+{
+  options = {
+    name = lib.mkOption {
+      type = lib.types.str;
+      default = config._module.args.name;
+      description = "Name";
+    };
+    type = lib.mkOption {
+      type = lib.types.enum [ "mdadm" ];
+      default = "mdadm";
+      internal = true;
+      description = "Type";
+    };
+    level = lib.mkOption {
+      type = lib.types.int;
+      default = 1;
+      description = "mdadm level";
+    };
+    metadata = lib.mkOption {
+      type = lib.types.enum [ "1" "1.0" "1.1" "1.2" "default" "ddf" "imsm" ];
+      default = "default";
+      description = "Metadata";
+    };
+    content = diskoLib.deviceType;
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = diskoLib.jsonType;
+      default =
+        lib.optionalAttrs (!isNull config.content) (config.content._meta [ "mdadm" config.name ]);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = {}: ''
+        echo 'y' | mdadm --create /dev/md/${config.name} \
+          --level=${toString config.level} \
+          --raid-devices=$(wc -l $disko_devices_dir/raid_${config.name} | cut -f 1 -d " ") \
+          --metadata=${config.metadata} \
+          --force \
+          --homehost=any \
+          $(tr '\n' ' ' < $disko_devices_dir/raid_${config.name})
+        udevadm trigger --subsystem-match=block; udevadm settle
+        ${lib.optionalString (!isNull config.content) (config.content._create {dev = "/dev/md/${config.name}";})}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = {}:
+        lib.optionalAttrs (!isNull config.content) (config.content._mount { dev = "/dev/md/${config.name}"; });
+      # TODO we probably need to assemble the mdadm somehow
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default =
+        lib.optional (!isNull config.content) (config.content._config "/dev/md/${config.name}");
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: (lib.optionals (!isNull config.content) (config.content._pkgs pkgs));
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/mdraid.nix b/types/mdraid.nix
new file mode 100644
index 0000000..6eb24bc
--- /dev/null
+++ b/types/mdraid.nix
@@ -0,0 +1,48 @@
+{ config, options, lib, diskoLib, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "mdraid" ];
+      internal = true;
+      description = "Type";
+    };
+
+    name = lib.mkOption {
+      type = lib.types.str;
+      description = "Name";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev: {
+        deviceDependencies.mdadm.${config.name} = [ dev ];
+      };
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        echo "${dev}" >> $disko_devices_dir/raid_${config.name}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }:
+        { };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev: [ ];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.mdadm ];
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/nodev.nix b/types/nodev.nix
new file mode 100644
index 0000000..4d4a11e
--- /dev/null
+++ b/types/nodev.nix
@@ -0,0 +1,72 @@
+{ lib, config, options, diskoLib, optionTypes, rootMountPoint, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "nodev" ];
+      default = "nodev";
+      internal = true;
+      description = "Device type";
+    };
+    fsType = lib.mkOption {
+      type = lib.types.str;
+      description = "File system type";
+    };
+    device = lib.mkOption {
+      type = lib.types.str;
+      default = "none";
+      description = "Device to use";
+    };
+    mountpoint = lib.mkOption {
+      type = optionTypes.absolute-pathname;
+      default = config._module.args.name;
+      description = "Location to mount the file system at";
+    };
+    mountOptions = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ "defaults" ];
+      description = "Options to pass to mount";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = diskoLib.jsonType;
+      default = { };
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = {}: "";
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = {}: {
+        fs.${config.mountpoint} = ''
+          if ! findmnt ${config.fsType} "${rootMountPoint}${config.mountpoint}" > /dev/null 2>&1; then
+            mount -t ${config.fsType} ${config.device} "${rootMountPoint}${config.mountpoint}" \
+            ${lib.concatMapStringsSep " " (opt: "-o ${opt}") config.mountOptions} \
+            -o X-mount.mkdir
+          fi
+        '';
+      };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = [{
+        fileSystems.${config.mountpoint} = {
+          device = config.device;
+          fsType = config.fsType;
+          options = config.mountOptions;
+        };
+      }];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ ];
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/partition.nix b/types/partition.nix
new file mode 100644
index 0000000..7ca0379
--- /dev/null
+++ b/types/partition.nix
@@ -0,0 +1,100 @@
+{ config, options, lib, diskoLib, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "partition" ];
+      internal = true;
+      description = "Type";
+    };
+    part-type = lib.mkOption {
+      type = lib.types.enum [ "primary" "logical" "extended" ];
+      default = "primary";
+      description = "Partition type";
+    };
+    fs-type = lib.mkOption {
+      type = lib.types.nullOr (lib.types.enum [ "btrfs" "ext2" "ext3" "ext4" "fat16" "fat32" "hfs" "hfs+" "linux-swap" "ntfs" "reiserfs" "udf" "xfs" ]);
+      default = null;
+      description = "Filesystem type to use";
+    };
+    name = lib.mkOption {
+      type = lib.types.nullOr lib.types.str;
+      description = "Name of the partition";
+    };
+    start = lib.mkOption {
+      type = lib.types.str;
+      default = "0%";
+      description = "Start of the partition";
+    };
+    end = lib.mkOption {
+      type = lib.types.str;
+      default = "100%";
+      description = "End of the partition";
+    };
+    index = lib.mkOption {
+      type = lib.types.int;
+      # TODO find a better way to get the index
+      default = lib.toInt (lib.head (builtins.match ".*entry ([[:digit:]]+)]" config._module.args.name));
+      description = "Index of the partition";
+    };
+    flags = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ ];
+      description = "Partition flags";
+    };
+    bootable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      description = "Whether to make the partition bootable";
+    };
+    content = diskoLib.partitionType;
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev:
+        lib.optionalAttrs (!isNull config.content) (config.content._meta dev);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev, type }: ''
+        ${lib.optionalString (type == "gpt") ''
+          parted -s ${dev} -- mkpart ${config.name} ${diskoLib.maybeStr config.fs-type} ${config.start} ${config.end}
+        ''}
+        ${lib.optionalString (type == "msdos") ''
+          parted -s ${dev} -- mkpart ${config.part-type} ${diskoLib.maybeStr config.fs-type} ${diskoLib.maybeStr config.fs-type} ${config.start} ${config.end}
+        ''}
+        # ensure /dev/disk/by-path/..-partN exists before continuing
+        udevadm trigger --subsystem-match=block; udevadm settle
+        ${lib.optionalString (config.bootable) ''
+          parted -s ${dev} -- set ${toString config.index} boot on
+        ''}
+        ${lib.concatMapStringsSep "" (flag: ''
+          parted -s ${dev} -- set ${toString config.index} ${flag} on
+        '') config.flags}
+        # ensure further operations can detect new partitions
+        udevadm trigger --subsystem-match=block; udevadm settle
+        ${lib.optionalString (!isNull config.content) (config.content._create {dev = (diskoLib.deviceNumbering dev config.index);})}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }:
+        lib.optionalAttrs (!isNull config.content) (config.content._mount { dev = (diskoLib.deviceNumbering dev config.index); });
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev:
+        lib.optional (!isNull config.content) (config.content._config (diskoLib.deviceNumbering dev config.index));
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: lib.optionals (!isNull config.content) (config.content._pkgs pkgs);
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/swap.nix b/types/swap.nix
new file mode 100644
index 0000000..60a7aff
--- /dev/null
+++ b/types/swap.nix
@@ -0,0 +1,56 @@
+{ diskoLib, config, options, lib, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "swap" ];
+      internal = true;
+      description = "Type";
+    };
+    randomEncryption = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      description = "Whether to randomly encrypt the swap";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev: { };
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        mkswap ${dev}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }: {
+        fs.${dev} = ''
+          if ! swapon --show | grep -q '^${dev} '; then
+            swapon ${dev}
+          fi
+        '';
+      };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev: [{
+        swapDevices = [{
+          device = dev;
+          randomEncryption = config.randomEncryption;
+        }];
+      }];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.gnugrep pkgs.util-linux ];
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/table.nix b/types/table.nix
new file mode 100644
index 0000000..fee81a5
--- /dev/null
+++ b/types/table.nix
@@ -0,0 +1,63 @@
+{ config, options, lib, diskoLib, subTypes, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "table" ];
+      internal = true;
+      description = "Partition table";
+    };
+    format = lib.mkOption {
+      type = lib.types.enum [ "gpt" "msdos" ];
+      default = "gpt";
+      description = "The kind of partition table";
+    };
+    partitions = lib.mkOption {
+      type = lib.types.listOf subTypes.partition;
+      default = [ ];
+      description = "List of partitions to add to the partition table";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev:
+        diskoLib.deepMergeMap (partition: partition._meta dev) config.partitions;
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        parted -s ${dev} -- mklabel ${config.format}
+        ${lib.concatMapStrings (partition: partition._create {inherit dev; type = config.format;} ) config.partitions}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }:
+        let
+          partMounts = diskoLib.deepMergeMap (partition: partition._mount { inherit dev; }) config.partitions;
+        in
+        {
+          dev = ''
+            ${lib.concatMapStrings (x: x.dev or "") (lib.attrValues partMounts)}
+          '';
+          fs = partMounts.fs or { };
+        };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev:
+        map (partition: partition._config dev) config.partitions;
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs:
+        [ pkgs.parted pkgs.systemdMinimal ] ++ lib.flatten (map (partition: partition._pkgs pkgs) config.partitions);
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/zfs.nix b/types/zfs.nix
new file mode 100644
index 0000000..b30ad44
--- /dev/null
+++ b/types/zfs.nix
@@ -0,0 +1,47 @@
+{ config, options, lib, diskoLib, ... }:
+{
+  options = {
+    type = lib.mkOption {
+      type = lib.types.enum [ "zfs" ];
+      internal = true;
+      description = "Type";
+    };
+    pool = lib.mkOption {
+      type = lib.types.str;
+      description = "Name of the ZFS pool";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev: {
+        deviceDependencies.zpool.${config.pool} = [ dev ];
+      };
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { dev }: ''
+        echo "${dev}" >> $disko_devices_dir/zfs_${config.pool}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { dev }:
+        { };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = dev: [ ];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.zfs ];
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/zfs_dataset.nix b/types/zfs_dataset.nix
new file mode 100644
index 0000000..704e378
--- /dev/null
+++ b/types/zfs_dataset.nix
@@ -0,0 +1,103 @@
+{ config, options, lib, diskoLib, optionTypes, rootMountPoint, ... }:
+{
+  options = {
+    name = lib.mkOption {
+      type = lib.types.str;
+      default = config._module.args.name;
+      description = "Name of the dataset";
+    };
+    type = lib.mkOption {
+      type = lib.types.enum [ "zfs_dataset" ];
+      default = "zfs_dataset";
+      internal = true;
+      description = "Type";
+    };
+    zfs_type = lib.mkOption {
+      type = lib.types.enum [ "filesystem" "volume" ];
+      description = "The type of the dataset";
+    };
+    options = lib.mkOption {
+      type = lib.types.attrsOf lib.types.str;
+      default = { };
+      description = "Options to set for the dataset";
+    };
+    mountOptions = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ "defaults" ];
+      description = "Mount options";
+    };
+
+    # filesystem options
+    mountpoint = lib.mkOption {
+      type = lib.types.nullOr optionTypes.absolute-pathname;
+      default = null;
+      description = "Path to mount the dataset to";
+    };
+
+    # volume options
+    size = lib.mkOption {
+      type = lib.types.nullOr lib.types.str; # TODO size
+      default = null;
+      description = "Size of the dataset";
+    };
+
+    content = diskoLib.partitionType;
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo diskoLib.jsonType;
+      default = dev:
+        lib.optionalAttrs (!isNull config.content) (config.content._meta dev);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = { zpool }: ''
+        zfs create ${zpool}/${config.name} \
+          ${lib.concatStringsSep " " (lib.mapAttrsToList (n: v: "-o ${n}=${v}") config.options)} \
+          ${lib.optionalString (config.zfs_type == "volume") "-V ${config.size}"}
+        ${lib.optionalString (config.zfs_type == "volume") ''
+          udevadm trigger --subsystem-match=block; udevadm settle
+          ${lib.optionalString (!isNull config.content) (config.content._create {dev = "/dev/zvol/${zpool}/${config.name}";})}
+        ''}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = { zpool }:
+        lib.optionalAttrs (config.zfs_type == "volume" && !isNull config.content) (config.content._mount { dev = "/dev/zvol/${zpool}/${config.name}"; }) //
+        lib.optionalAttrs (config.zfs_type == "filesystem" && config.options.mountpoint or "" != "none") {
+          fs.${config.mountpoint} = ''
+            if ! findmnt ${zpool}/${config.name} "${rootMountPoint}${config.mountpoint}" > /dev/null 2>&1; then
+              mount ${zpool}/${config.name} "${rootMountPoint}${config.mountpoint}" \
+              -o X-mount.mkdir \
+              ${lib.concatMapStringsSep " " (opt: "-o ${opt}") config.mountOptions} \
+              ${lib.optionalString ((config.options.mountpoint or "") != "legacy") "-o zfsutil"} \
+              -t zfs
+            fi
+          '';
+        };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = zpool:
+        (lib.optional (config.zfs_type == "volume" && !isNull config.content) (config.content._config "/dev/zvol/${zpool}/${config.name}")) ++
+        (lib.optional (config.zfs_type == "filesystem" && config.options.mountpoint or "" != "none") {
+          fileSystems.${config.mountpoint} = {
+            device = "${zpool}/${config.name}";
+            fsType = "zfs";
+            options = config.mountOptions ++ lib.optional ((config.options.mountpoint or "") != "legacy") "zfsutil";
+          };
+        });
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.util-linux ] ++ lib.optionals (!isNull config.content) (config.content._pkgs pkgs);
+      description = "Packages";
+    };
+  };
+}
diff --git a/types/zpool.nix b/types/zpool.nix
new file mode 100644
index 0000000..18f21cf
--- /dev/null
+++ b/types/zpool.nix
@@ -0,0 +1,110 @@
+{ config, options, lib, diskoLib, optionTypes, subTypes, rootMountPoint, ... }:
+{
+  options = {
+    name = lib.mkOption {
+      type = lib.types.str;
+      default = config._module.args.name;
+      description = "Name of the ZFS pool";
+    };
+    type = lib.mkOption {
+      type = lib.types.enum [ "zpool" ];
+      default = "zpool";
+      internal = true;
+      description = "Type";
+    };
+    mode = lib.mkOption {
+      type = lib.types.str; # TODO zfs modes
+      default = "";
+      description = "Mode of the ZFS pool";
+    };
+    options = lib.mkOption {
+      type = lib.types.attrsOf lib.types.str;
+      default = { };
+      description = "Options for the ZFS pool";
+    };
+    rootFsOptions = lib.mkOption {
+      type = lib.types.attrsOf lib.types.str;
+      default = { };
+      description = "Options for the root filesystem";
+    };
+    mountpoint = lib.mkOption {
+      type = lib.types.nullOr optionTypes.absolute-pathname;
+      default = null;
+      description = "The mountpoint of the pool";
+    };
+    mountOptions = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ "defaults" ];
+      description = "Options to pass to mount";
+    };
+    datasets = lib.mkOption {
+      type = lib.types.attrsOf subTypes.zfs_dataset;
+      description = "List of datasets to define";
+    };
+    _meta = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = diskoLib.jsonType;
+      default =
+        diskoLib.deepMergeMap (dataset: dataset._meta [ "zpool" config.name ]) (lib.attrValues config.datasets);
+      description = "Metadata";
+    };
+    _create = diskoLib.mkCreateOption {
+      inherit config options;
+      default = {}: ''
+        zpool create ${config.name} \
+          ${config.mode} \
+          ${lib.concatStringsSep " " (lib.mapAttrsToList (n: v: "-o ${n}=${v}") config.options)} \
+          ${lib.concatStringsSep " " (lib.mapAttrsToList (n: v: "-O ${n}=${v}") config.rootFsOptions)} \
+          $(tr '\n' ' ' < $disko_devices_dir/zfs_${config.name})
+        ${lib.concatMapStrings (dataset: dataset._create {zpool = config.name;}) (lib.attrValues config.datasets)}
+      '';
+    };
+    _mount = diskoLib.mkMountOption {
+      inherit config options;
+      default = {}:
+        let
+          datasetMounts = diskoLib.deepMergeMap (dataset: dataset._mount { zpool = config.name; }) (lib.attrValues config.datasets);
+        in
+        {
+          dev = ''
+            zpool list '${config.name}' >/dev/null 2>/dev/null || zpool import '${config.name}'
+            ${lib.concatMapStrings (x: x.dev or "") (lib.attrValues datasetMounts)}
+          '';
+          fs = datasetMounts.fs // lib.optionalAttrs (!isNull config.mountpoint) {
+            ${config.mountpoint} = ''
+              if ! findmnt ${config.name} "${rootMountPoint}${config.mountpoint}" > /dev/null 2>&1; then
+                mount ${config.name} "${rootMountPoint}${config.mountpoint}" \
+                ${lib.optionalString ((config.options.mountpoint or "") != "legacy") "-o zfsutil"} \
+                ${lib.concatMapStringsSep " " (opt: "-o ${opt}") config.mountOptions} \
+                -o X-mount.mkdir \
+                -t zfs
+              fi
+            '';
+          };
+        };
+    };
+    _config = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      default = [
+        (map (dataset: dataset._config config.name) (lib.attrValues config.datasets))
+        (lib.optional (!isNull config.mountpoint) {
+          fileSystems.${config.mountpoint} = {
+            device = config.name;
+            fsType = "zfs";
+            options = config.mountOptions ++ lib.optional ((config.options.mountpoint or "") != "legacy") "zfsutil";
+          };
+        })
+      ];
+      description = "NixOS configuration";
+    };
+    _pkgs = lib.mkOption {
+      internal = true;
+      readOnly = true;
+      type = lib.types.functionTo (lib.types.listOf lib.types.package);
+      default = pkgs: [ pkgs.util-linux ] ++ lib.flatten (map (dataset: dataset._pkgs pkgs) (lib.attrValues config.datasets));
+      description = "Packages";
+    };
+  };
+}