CompactFlash Design Considerations (Windows Embedded Standard 2009)


By adding the Enhanced Write Filter (EWF) component to your configuration, you can reduce the wear on your CompactFlash device. Before you create your configuration for a CompactFlash device, be aware of the following considerations:

  • The instructions provided in How to Configure EWF for CompactFlash show how to implement EWF RAM Reg Mode. In EWF RAM Reg mode, the EWF volume configuration information is stored in the registry, which is protected by EWF.
    To disable EWF, you must use the EWFMGR commitanddisable command. Because the EWF configuration information is protected by EWF, committing the overlay writes all changes to the protected volume, including the EWF disable command.
    Before you create your CompactFlash run-time image, familiarize yourself with EWF RAM Reg Mode.
  • Typically, CompactFlash devices are marked as removable and cannot be partitioned by using Windows XP partitioning tools. Some manufacturers include utilities to mark their CompactFlash devices as non-removable (fixed) to allow additional partitioning. Use your manufacturer's CompactFlash partitioning tools to edit the partition sizes of your CompactFlash device.
  • The instructions provided in How to Configure EWF for CompactFlash require a CompactFlash to IDE adapter. USB CompactFlash card readers are not supported.
  • You should disable pagefile support on your run-time image, or, if possible, relocate your pagefile to a non-protected volume. Using a pagefile can add a significant amount of overhead in the RAM overlay. For more information, see Changing the Location of the Pagefile.

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