Product Documentation


Before you start creating an OS layer, be sure to meet these requirements.

Basic requirements

  • Start with a fresh operating system image, preferably from your hypervisor, so that the operating system is partially optimized for your environment.
  • Make sure that the operating system image is not in a domain. Ensure that the image gets its IP address from DHCP. Otherwise, you will not be able to install the OS Machine Tools.
  • Ensure that the virtual machine for your OS layer is master boot record (MBR) partitioned, rather than GUID partition table (GPT) partitioned.
  • Locate the OS Machine Tools in the installation package.
  • If you want to use an optimization script or an answer file for unattended installation, use the tools included in the installation package. For more information, see:


    Avoid using third-party scripts, because they can change services and features that the App Layering service uses, for example, Universal Plug and Play and the 8.3 file names setting.

Additional Citrix XenServer requirement

  • XenCenter uses Port 5900 to access the console on each virtual machine. Make sure that this port is open on your OS image. Otherwise, the packaging machine and published images will not work until you restart the virtual machine.

Additional VMware vSphere

  • The Paravirtual SCSI controller is not supported. You must use the default controller (SCSI BusLogic). The LSI Logic SAS controller type is supported. If you change the SCSI controller type to anything else, the OS Layer import will fail.