While reading the QuickStart for disko, I saw this line:

However, you will need to include the partitioning and formatting configurations that you copied into /tmp/disk-config.nix in your configuration, rather than allowing NixOS to generate information about your file systems.

Is there a reason why one shouldn't just let NixOS generation information about my file systems? I'd like for my installs to be as vanilla as possible (as though they were completely installed manually) so I'm curious what pros and cons there are to just continuing the normal NixOS way

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);
      };
    };
  };
}