nixos-servers/modules/disk-config.nix

{
  disko.devices = {
    disk = {
      vdb = {
        device = "/dev/nvme0n1";
        type = "disk";
        content = {
          type = "gpt";
          partitions = {
            ESP = {
              type = "EF00";
              size = "500M";
              content = {
                type = "filesystem";
                format = "vfat";
                mountpoint = "/boot";
              };
            };
            root = {
              end = "-4G";
              content = {
                type = "filesystem";
                format = "btrfs";
                mountpoint = "/";
              };
            };
            swap = { size = "100%"; };
          };
        };
      };
    };
  };
}