I'm trying to set up a ZFS root with disko. Without mountpoint set on the pool, the pool ends up mounted by disko at /mnt/zpool. So I set rootFsOptions.mountpoint = "/" which made the installer environment happy, but now the stage1 is failing with

mounting zpool on /...
stage 2 init script (/mnt-root//nix/store/...) not found

In reply to @bashfulrobot.:matrix.org
Qq. Do I have to add disko to my config? Or can I just write a nix file and run against it? Then run nix-install and leverage what it created?

In reply to @matthewcroughan:defenestrate.it
You can do either, but it's much nicer if it's in your config, since then you'll get things mounted automatically based on your disko config

In reply to @sigmasquadron:matrix.org
bold choice to use BTRFS' RAID system.

Trying to setup LUKS+ZFS with Disko, I get prompted for my password, but right after I get this error.

/nix/store/ix2hsx2myrkpiw6gs8i06nbgjp49zdik-disko/bin/disko: line 128: cryptsetup: command not found

    NIX_TOP_LEVEL_PATH=$(nix build --impure -I nixos-config=./machines/gerd.nix --json --expr "(import <nixpkgs/nixos> {}).config.system.build.toplevel" | jq -r '.[].outputs.out')
    NIX_DISKO_SCRIPT=$(nix build --impure -I nixos-config=./machines/gerd.nix --json --expr "(import <nixpkgs/nixos> {}).config.system.build.diskoScriptNoDeps" | jq -r '.[].outputs.out')

    nixos-anywhere --store-paths "$NIX_DISKO_SCRIPT" "$NIX_TOP_LEVEL_PATH" "$USERNAME@$IP"

Works just fine without LUKS.

{ lib, ... }:

let
  makeZFSDatasets = datasets: (lib.mapAttrs' (n: v: lib.nameValuePair v.dataset ({
      type = "zfs_fs";
      mountpoint = n;
      options.mountpoint = "legacy";
  } // (if v ? extra then v.extra else {}))) datasets);
in {
  disko.devices = {
    disk.disk1 = {
      type = "disk";
      device = lib.mkDefault "/dev/sda";
      content = {
        type = "gpt";
        partitions = {
          boot = {
            name = "boot";
            size = "1M";
            type = "EF02";
          };
          esp = {
            name = "ESP";
            size = "500M";
            type = "EF00";
            content = {
              type = "filesystem";
              format = "vfat";
              mountpoint = "/boot";
            };
          };

          luks = {
            size = "100%";
            content = {
              type = "luks";
              name = "cryptroot";
              settings.allowDiscards = true;
              # passwordFile = "/tmp/luks.pass";

              content = {
                type = "zfs";
                pool = "rpool";
              };
            };
          };
        };
      };
    };

    zpool = {
      rpool = {
        type = "zpool";
        # rootFsOptions.compression = "zstd";
        rootFsOptions = {
          compression = "on";
          atime = "off";
          acltype = "posixacl";
          xattr = "sa";

          # test
          # "com.sun:auto-snapshot" = "false";
          # "com.klarasystems:vdev_zaps_v2" = "false";
        };

        datasets = let
          baseDatasets = {
            "/" = { dataset = "root"; extra = { postCreateHook = "zfs snapshot rpool/root@blank"; }; };
            "/nix".dataset = "local/nix";
            "/state/stash".dataset = "local/stash";
            "/state/home".dataset = "safe/home";
            "/state/root".dataset = "safe/persistent";

            # extra datasets
            "/srv/forgejo" = { dataset = "safe/svcs/forgejo"; extra.options.quota = "5G"; };
          };
        in (makeZFSDatasets baseDatasets);
      };
    };
  };
}