nix/nixos/hosts/warsaw-ovh-01/disks.nix

{
  # https://github.com/nix-community/disko/blob/master/example/boot-raid1.nix
  imports = [ ../../common/services/snapper.nix ];

  # extra configs not present in the standard config above
  services.snapper.configs.Storage = {
    TIMELINE_CREATE = true;
    TIMELINE_CLEANUP = true;
    SUBVOLUME = "/Storage";
  };
  
  services.btrfs.autoScrub.enable = true;
  services.btrfs.autoScrub.interval = "weekly";

  disko.devices = {
    disk = {
      sda = {
        type = "disk"; 
        device = "/dev/sda";
        content = {
          type = "gpt";
          partitions = {
            BOOT = {
              size = "1M"; 
              type = "EF02"; # GRUB MBR
            };
            ESP = {
              size = "500M";
              type = "EF00";
              content = {
                type = "mdraid";
                name = "boot";
              };
            };
            mdadm = {
              size = "100%";
              content = {
                type = "mdraid";
                name = "raid1";
              };
            };
          };
        };
      };

      sdb = {
        type = "disk"; 
        device = "/dev/sdb";
        content = {
          type = "gpt";
          partitions = {
            BOOT = {
              size = "1M"; 
              type = "EF02"; # GRUB MBR
            };
            ESP = {
              size = "500M";
              type = "EF00";
              content = {
                type = "mdraid";
                name = "boot";
              };
            };
            mdadm = {
              size = "100%";
              content = {
                type = "mdraid";
                name = "raid1";
              };
            };
          };
        };
      };
    };

    mdadm = {
      boot = {
        type = "mdadm";
        level = 1;
        metadata = "1.0";
        content = {
          type = "filesystem";
          format = "vfat";
          mountpoint = "/boot";
          mountOptions = [ "umask=0077" ];
        };
      };
      raid1 = {
        type = "mdadm";
        level = 1;
        content = {
          type = "gpt";
          partitions = {
            LUKS-ROOT = { 
              start = "550MiB";
              end = "100%";
              content = {
                type = "luks";
                name = "ROOT";
                extraOpenArgs = [ "--allow-discards" ];
                content = {
                  type = "btrfs";
                  extraArgs = [ "-f" ];
                  subvolumes = {
                    "/root" = {
                      mountpoint = "/";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # root
                    "/home" = {
                      mountpoint = "/home";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # home
                    "/nix" = {
                      mountpoint = "/nix";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # nix
                    "/Storage" = {
                      mountpoint = "/Storage";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # Storage
                    # SNAPSHOT SUBVOLS
                    "/root/.snapshots" = {
                      mountpoint = "/.snapshots";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # root
                    "/home/.snapshots" = {
                      mountpoint = "/home/.snapshots";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # home
                    "/nix/.snapshots" = {
                      mountpoint = "/nix/.snapshots";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # nix
                    "/Storage/.snapshots" = {
                      mountpoint = "/Storage/.snapshots";
                      mountOptions = [ "compress=zstd" "noatime" ];
                    }; # Storage
                  }; # subvolumes
                }; # content.content
              }; # content
            }; # partition 2 (/ BTRFS)
          };
        };
      };
    };
  };  
}