Share via

Configure EWF RAM Reg Mode (Standard 8)

  • Article

7/8/2014

Learn how to configure Enhanced Write Filter (EWF) RAM Reg mode on your Windows Embedded 8 Standard (Standard 8) device.

Enhanced Write Filter (EWF) RAM Reg mode stores overlay data in RAM and EWF configuration information in the registry. Because EWF RAM overlays store the data cache in RAM, your device may require additional RAM. In addition, because the data cache is stored in volatile memory, the data cache is lost when the system restarts.

Additionally, because EWF configuration information is stored in the registry, it is typically protected by EWF. You must use the ewfmgr -commitanddisable command to apply any changes to EWF.

Tip

You can also protect multiple volumes by using EWF RAM Reg mode. For more information, see Protect Multiple Volumes By Using RAM Reg Mode

To configure EWF RAM Reg mode

  1. Create a working configuration by using Image Configuration Editor (ICE).

  2. Add the Enhanced Write Filter module to your configuration.

  3. On the Validate menu, click Add Required Modules.

  4. Resolve any errors listed in the Messages pane.

  5. In the Configuration File pane, expand the Lockdown node, and then select Enhanced Write Filter. The EWF configuration settings appear in the settings pane.

  6. Change the following default settings for Enhanced Write Filter:

    • In the Filter view by box, select 4 Specialize.
    • In the EWFMode box, make sure that RamReg is selected.
    • Right-click the ProtectedVolumes settings, and then click Insert New Volume.
    • Expand the Volume node.
    • Set the Key value to any unique number.
    • For the DiskNumber property, type the disk number that contains the volume that you want to protect.
    • For the PartitionNumber property, type the partition number for the volume that you want to protect.

    Note

    You can protect multiple volumes by adding additional volumes to the EWF configuration.

  7. Save the configuration file.

  8. Make sure that there is additional space on the media where you plan to deploy your run-time image. During the EWF installer phase, EWF creates the EWF volume on the media that will contain metadata information about the EWF configuration.

    The media that you deploy to cannot have more than three partitions and must support partitioning.

  9. Deploy the run-time image and start the device.

  10. After the installation process is complete, verify the status of EWF by typing the following command line.

    ewfmgr -all

    By default, EWF should report that it is disabled on all drives.

  11. Enable EWF by typing the following command line:

    ewfmgr c: -enable

  12. Restart the system.

  13. Verify that EWF is correctly configured by typing the following command at a command prompt:

    ewfmgr c:

    Ewfmgr should report that EWF is enabled and provide a current status of the EWF RAM overlay.

    Note

    If you are using an intermediary hard disk, copy the run-time image to the CompactFlash device after verifying that EWF is configured correctly.

Notes

You can also use Image Builder Wizard (IBW) to install Enhanced Write Filter module. The default installation of the module configures EWF in RAM Reg mode and protects all volumes on the computer.

See Also

Concepts

EWF Installation and Configuration
EWF Modes
Troubleshooting EWF
EWF Performance Considerations