nixos-config/nixos/machines/orbi/disko-config.nix

# nix run github:nix-community/disko -- --mode zap_create_mount ./disko-config.nix
# nixos-generate-config --no-filesystems --root /mnt
# vim /mnt/configuration.nix
# nixos-install
{ config, lib, ... }:
let
  disks = [ "sda" "sdb" ];
in
{
  # ZFS already has its own scheduler. Without this my(@Artturin) computer froze for a second when i nix build something.
  # copied from : https://github.com/numtide/srvos/blob/main/nixos/common/zfs.nix

  services.udev.extraRules = lib.optionalString (config.boot.zfs.enabled) ''
    ACTION=="add|change", KERNEL=="sd[a-z]*[0-9]*|mmcblk[0-9]*p[0-9]*|nvme[0-9]*n[0-9]*p[0-9]*", ENV{ID_FS_TYPE}=="zfs_member", ATTR{../queue/scheduler}="none"
  '';

  disko.devices = {
    disk =
      lib.genAttrs disks (disk: {
        name = disk;
        type = "disk";
        device = "/dev/${disk}";
        content = {
          type = "table";
          format = "gpt";
          partitions = [
            {
              name = "ESP";
              start = "0";
              end = "500MiB";
              bootable = true;
              content = {
                type = "filesystem";
                format = "vfat";
                mountpoint = "/boot_${disk}";
                mountOptions = [ "defaults" ];
              };
            }
            {
              name = "zfs";
              start = "500MiB";
              size = "500GB";
              content = {
                type = "luks";
                name = "root_${disk}";
                settings = {
                  # if you want to use the key for interactive login be sure there is no trailing newline
                  # for example use `echo -n "password" > /tmp/secret.key`
                  keyFile = "/tmp/secret.key";
                  allowDiscards = true;
                };
                content = {
                  type = "zfs";
                  pool = "zroot";
                };
              };
            }
            {
              name = "zfs";
              size = "100%";
              content = {
                type = "luks";
                settings = {
                  # if you want to use the key for interactive login be sure there is no trailing newline
                  # for example use `echo -n "password" > /tmp/secret.key`
                  keyFile = "/tmp/secret.key";
                  allowDiscards = true;
                };
                name = "media_${disk}";
                content = {
                  type = "zfs";
                  pool = "zmedia";
                };
              };
            }
          ];
        };
      }
      );


    zpool = {

      zroot = {
        type = "zpool";
        mode = "mirror";
        rootFsOptions = {
          mountpoint = "none";
          canmount = "off";
          compression = "lz4";
        };
        datasets = {
          "root" = {
            type = "zfs_fs";
            mountpoint = "/";
            options = {
              mountpoint = "legacy";
              compression = "lz4";
            };
          };
          "store" = {
            type = "zfs_fs";
            mountpoint = "/nix/store";
            options = {
              mountpoint = "legacy";
              compression = "lz4";
            };
          };
        };
      };

      # `zpool import -f zraid` once on the first boot and reboot
      zmedia = {
        type = "zpool";
        rootFsOptions = {
          mountpoint = "none";
          canmount = "off";
        };
        datasets = {
          "media" = {
            type = "zfs_fs";
            mountpoint = "/media";
            options = {
              mountpoint = "legacy";
              compression = "lz4";
              "com.sun:auto-snapshot:daily" = false;
              "com.sun:auto-snapshot:weekly" = false;
              "com.sun:auto-snapshot:monthly" = false;
            };
          };
          # todo make sure this disk has some minimum space
          "nextcloud" = {
            type = "zfs_fs";
            mountpoint = "/var/lib/nextcloud/";
            options = {
              mountpoint = "legacy";
              compression = "lz4";
              "com.sun:auto-snapshot:hourly" = true;
              "com.sun:auto-snapshot:daily" = true;
              "com.sun:auto-snapshot:weekly" = false;
              "com.sun:auto-snapshot:monthly" = false;
            };
          };
        };
      };
    };
  };

}