anchor.diff:          '';
       };
   
  -    fileSystems."/" = {
  -      device = "/dev/disk/by-label/nixos";
  -      autoResize = true;
  -      fsType = "ext4";
  -    };
  +    fileSystems = {
  +      "/" = {
  +        device = "/dev/disk/by-label/nixos";
  +        autoResize = true;
  +        fsType = "ext4";
  +      };
  +    } // (lib.optionalAttrs (cfg.extraDisk != null) {
  +      ${cfg.extraDisk.mountPoint} = {
  +        device = "/dev/disk/by-label/" + cfg.extraDisk.label;
  +        autoResize = true;
  +        fsType = "ext4";
  +      };
  +    });
   
       boot.growPartition = true;
       boot.loader.grub.device = "/dev/sda";
  
positive.code:           Run <literal>VBoxManage modifyvm --help</literal> to see more options.
          '';
       };
      };
    };
  
  
negative.code:           VBoxManage storagectl "$vmName" --name SATA --add sata --portcount 4 --bootable on --hostiocache on
            VBoxManage storageattach "$vmName" --storagectl SATA --port 0 --device 0 --type hdd \
              --medium disk.vmdk
            ${optionalString (cfg.extraDisk != null) ''
              VBoxManage storageattach "$vmName" --storagectl SATA --port 1 --device 0 --type hdd \
              --medium data-disk.vmdk
            ''}
  
            echo "exporting VirtualBox VM..."
            mkdir -p $out
  