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Microsoft-Windows-Embedded-UnifiedWriteFilter (Industry 8.1)

  • Article

7/8/2014

Review the settings and examples of the Microsoft-Windows-Embedded-UnifiedWriteFilter feature package for Windows System Image Manager (SIM) in Windows Embedded 8.1 Industry (Industry 8.1).

You can use Unified Write Filter (UWF) in your Windows Embedded 8.1 Industry (Industry 8.1) device to help protect your physical storage media, including most standard writable storage types that are supported by Windows 8.1, such as physical hard disks, solid-state drives, internal USB devices, external SATA devices, and so on. You can also use UWF to make read-only media appear to the OS as a writeable volume.

Important

You cannot use UWF to protect external USB devices or flash drives.

UWF intercepts all write attempts to a protected volume and redirects those write attempts to a virtual overlay. This improves the reliability and stability of your device and reduces the wear on write-sensitive media, such as flash memory media like solid-state drives.

The overlay does not mirror the entire volume, but dynamically grows to keep track of redirected writes. Generally the overlay is stored in system memory, although you can cache a portion of the overlay on a physical volume.

Note

UWF fully supports the NTFS system; however, during device startup, NTFS file system journal files can write to a protected volume before UWF has loaded and started protecting the volume.

Settings available in Windows SIM

UWF basic settings

Setting

Description

AddAllVolumes

Specifies whether to protect all volumes with UWF.

Binding

Specifies whether to bind the physical volume by drive letter or by volume name.

BootStatusPolicy

Specifies the display policy of Windows Boot Loader errors.

DisableAutoDefrag

Specifies whether to disable automatic disk defragmentation.

DomainSecretKeyPersisted

Specifies whether to persist the domain secret key on a device.

OverlayCriticalThreshold

Specifies the critical threshold size, in MB, for the UWF overlay.

OverlayMaximumSize

Specifies the maximum overlay size, in MB, for the UWF overlay.

OverlayType

Specifies the type of overlay storage used by UWF.

OverlayWarningThreshold

Specifies the overlay warning threshold size, in MB, for UWF.

RegistryExceptionsUserDefined

Specifies the registry keys to exclude from being filtered. When a registry key is in the exclusion list, all writes to that registry key bypass UWF filtering and are written directly to the registry and persist after the device restarts.

TSCALPersisted

Specifies whether the Terminal Services Client Access Licensing (TSCAL) registry key is in the UWF exclusion list.

ProtectedVolumeEntry settings

Setting

Description

Action

Specifies whether to add, modify, or remove this entry from the list.

DriveLetter

Specifies the drive letter of a volume protected by UWF.

FileExceptionsUserDefined

Specifies the full path of the files or folders on a protected volume to exclude from filtering by UWF.

Settings details

UWF basic settings

AddAllVolumes

Specifies whether to protect all volumes with UWF.

  • Type
    String

  • Values

    Value

    Description

    False

    Do not protect all volumes.

    This is the default value.

    True

    Protect all volumes.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | AddAllVolumes
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <AddAllVolumes>True</AddAllVolumes>
    </component>
</settings>

Binding

Specifies whether to bind the physical volume by drive letter or by volume name.

  • Type
    String

  • Values

    Value

    Description

    Loose Binding

    Binds the volume by drive letter (loose binding).

    Tight Binding

    Binds the volume by the volume name (tight binding).

    This is the default value.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | Binding
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <Binding>Loose Binding</Binding>
    </component>
</settings>

BootStatusPolicy

Specifies the display policy of Windows Boot Loader errors.

  • Type
    String

  • Values

    Value

    Description

    DisplayAllFailures

    Display all failures in the Windows Error Recovery window.

    IgnoreAllFailures

    Ignore all boot failures and start Industry 8.1 normally.

    This is the default value.

    IgnoreShutdownFailures

    Display only boot failures in the Windows Error Recovery window.

    IgnoreBootFailures

    Display only shutdown failures in the Windows Error Recovery window.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | BootStatusPolicy
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <BootStatusPolicy>IgnoreShutdownFailures</BootStatusPolicy>
    </component>
</settings>

DisableAutoDefrag

Specifies whether to disable automatic disk defragmentation.

  • Type
    String

  • Values

    Value

    Description

    False

    Do not disable automatic disk defragmentation.

    True

    Disable automatic disk defragmentation.

    This is the default value.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | DisableAutoDefrag
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <DisableAutoDefrag>False</DisableAutoDefrag>
    </component>
</settings>

DomainSecretKeyPersisted

Specifies whether to persist the domain secret key on a device.

  • Type
    String

  • Values

    Value

    Description

    False

    Do no persist the domain secret key on the device.

    True

    Persist the domain secret key on the device.

    This is the default value.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | DomainSecretKeyPersisted
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <DomainSecretKeyPersisted>False</DomainSecretKeyPersisted>
    </component>
</settings>

OverlayCriticalThreshold

Specifies the critical threshold size, in MB, for the UWF overlay.

  • Type
    Int32

  • Values

    Value

    Description

    Threshold

    The threshold size, in MB, for the UWF overlay.

    1024 is the default value.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | OverlayCriticalThreshold
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <OverlayCriticalThreshold>3048</OverlayCriticalThreshold>
    </component>
</settings>

OverlayMaximumSize

Specifies the maximum overlay size, in MB, for the UWF overlay.

  • Type
    Int32

  • Values

    Value

    Description

    OverlayMaxSize

    The maximum size, in MB, for the UWF overlay.

    1024 is the default value.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | OverlayMaximumSize
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <OverlayMaximumSize>3048</OverlayMaximumSize>
    </component>
</settings>

OverlayType

Specifies the type of overlay storage used by UWF.

  • Type
    String

  • Values

    Value

    Description

    RAM overlay

    Stores the overlay in RAM.

    This is the default value.

    Disk overlay

    Stores the overlay in a pre-allocated file on the system volume.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | OverlayType
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <OverlayType>Disk overlay</OverlayType>
    </component>
</settings>

OverlayWarningThreshold

Specifies the overlay warning threshold size, in MB, for UWF.

  • Type
    Int32

  • Values

    Value

    Description

    OverlayWarningThreshold

    The maximum size, in MB, for the UWF overlay.

    512 is the default value.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | OverlayWarningThreshold
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <OverlayWarningThreshold>256</OverlayWarningThreshold>
    </component>
</settings>

RegistryExceptionsUserDefined

Specifies the registry keys to exclude from being filtered. When a registry key is in the exclusion list, all writes to that registry key bypass UWF filtering and are written directly to the registry and persist after the device restarts.

  • Type
    String[]

  • Values

    Value

    Description

    RegistryExceptionKey

    Registry keys to exclude from being filtered.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | RegistryExceptionsUserDefined
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <RegistryExceptionsUserDefined>HKEY_LOCAL_MACHINE\COMPONENTS</RegistryExceptionsUserDefined>
    </component>
</settings>

TSCALPersisted

Specifies whether the Terminal Services Client Access Licensing (TSCAL) registry key is in the UWF exclusion list.

  • Type
    String

  • Values

    Value

    Description

    False

    The TSCAL registry key is not in the UWF exclusion list.

    True

    The TSCAL registry key is in the UWF exclusion list.

    This is the default value.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | TSCALPersisted
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <TSCALPersisted>False</TSCALPersisted>
    </component>
</settings>

ProtectedVolumeEntry settings

Action

Specifies whether to add, modify, or remove this entry from the list.

  • Values

    Value

    Description

    AddListItem

    Add a new entry the list.

    Modify

    Modify an existing entry.

    RemoveListItem

    Remove an entry from the list.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | ProtectedVolumeList | ProtectedVolumeEntry | Action
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <ProtectedVolumeList>
            <ProtectedVolumeEntry wcm:action="add">
                <DriveLetter>C:</DriveLetter>
            </ProtectedVolumeEntry>
        </ProtectedVolumeList>
    </component>
</settings>

DriveLetter

Specifies the drive letter of a volume protected by UWF.

  • Type
    String

  • Values

    Value

    Description

    DriveLetter

    Specifies the drive letter of a volume protected by UWF.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | ProtectedVolumeList | ProtectedVolumeEntry | DriveLetter
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <ProtectedVolumeList>
            <ProtectedVolumeEntry wcm:action="add">
                <DriveLetter>C:</DriveLetter>
            </ProtectedVolumeEntry>
        </ProtectedVolumeList>
    </component>
</settings>

FileExceptionsUserDefined

Specifies the full path of the files or folders on a protected volume to exclude from filtering by UWF.

  • Action
    String[]

  • Values

    Value

    Description

    FileExceptions

    Specifies the full path of the files or folders on a protected volume to exclude from filtering by UWF.
  • Parent hierarchy
    Microsoft-Windows-Embedded-UnifiedWriteFilter | ProtectedVolumeList | ProtectedVolumeEntry | FileExceptionsUserDefined
  • Valid passes
    specialize

  • XML example

    <settings pass="specialize">
    <component name="Microsoft-Windows-Embedded-UnifiedWriteFilter" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="NonSxS" xmlns:wcm="https://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
        <ProtectedVolumeList>
            <ProtectedVolumeEntry wcm:action="add">
                <FileExceptionsUserDefined>C:\User\Test\Test.log C:\User\Log</FileExceptionsUserDefined>
            </ProtectedVolumeEntry>
        </ProtectedVolumeList>
    </component>
</settings>

See Also

Reference

Unified Write Filter WMI provider reference

Concepts

Add lockdown and branding features to your image by using Windows SIM
Unified Write Filter
Overlay for Unified Write Filter (UWF)
Troubleshooting Unified Write Filter (UWF)