anchor.diff:            The size of the VirtualBox base image in MiB.
           '';
         };
  +      memorySize = mkOption {
  +        type = types.int;
  +        default = 1536;
  +        description = ''
  +          The amount of RAM the VirtualBox appliance can use in MiB.
  +        '';
  +      };
  +      vmDerivationName = mkOption {
  +        type = types.str;
  +        default = "nixos-ova-${config.system.nixos.label}-${pkgs.stdenv.system}";
  +        description = ''
  +          The name of the derivation for the VirtualBox appliance.
  +        '';
  +      };
  +      vmName = mkOption {
  +        type = types.str;
  +        default = "NixOS ${config.system.nixos.label} (${pkgs.stdenv.system})";
  +        description = ''
  +          The name of the VirtualBox appliance.
  +        '';
  +      };
  +      vmFileName = mkOption {
  +        type = types.str;
  +        default = "nixos-${config.system.nixos.label}-${pkgs.stdenv.system}.ova";
  +        description = ''
  +          The file name of the VirtualBox appliance.
  +        '';
  +      };
       };
     };
   
     config = {
       system.build.virtualBoxOVA = import ../../lib/make-disk-image.nix {
  -      name = "nixos-ova-${config.system.nixos.label}-${pkgs.stdenv.system}";
  +      name = cfg.vmDerivationName;
   
         inherit pkgs lib config;
         partitionTableType = "legacy";
  
positive.code:           VBoxManage internalcommands createrawvmdk -filename disk.vmdk -rawdisk $diskImage
  
            echo "creating VirtualBox VM..."
            vmName="NixOS ${config.system.nixos.label} (${pkgs.stdenv.system})"
            VBoxManage createvm --name "$vmName" --register \
              --ostype ${if pkgs.stdenv.system == "x86_64-linux" then "Linux26_64" else "Linux26"}
            VBoxManage modifyvm "$vmName" \
              --memory 1536 --acpi on --vram 32 \
              ${optionalString (pkgs.stdenv.system == "i686-linux") "--pae on"} \
              --nictype1 virtio --nic1 nat \
              --audiocontroller ac97 --audio alsa \
  
negative.code: 
            echo "exporting VirtualBox VM..."
            mkdir -p $out
            fn="$out/${cfg.vmFileName}"
            VBoxManage export "$vmName" --output "$fn"
  
            rm -v $diskImage
  