FBWF Manager

3/21/2011

The FBWF Manager is a command-line tool that is included in Windows Embedded Standard 7 to quickly integrate and prototype the FBWF (File-Based Write Filter). FBWF Manager is intended primarily for design-time use, but can also be used to configure FBWF at run time.

The FBWF Manager command-line syntax follows:

fbwfmgr  [ /? | /help /[switch] | /displayconfig |
 /overlaydetail | /enable | /disable | /addvolume [volumename] |
 /removevolume [volumename] [1|0] |
 /addexclusion [volumename] [file or directory path] |
 /removeexclusion [volumename] [file or directory path] |
 /setthreshold [threshold] | /setcompression [1|0] |
 /setpreallocation [1|0] | /commit [volumename] [file path] |
 /restore [volumename] [file path] | /setsizedisplay [1|0] |
 /getvirtualsize [volumename] | /getactualsize [volumename]

The following table describes the command-line switches.

Switch Description

?

Displays usage and help.

addexclusion

Adds a write-through path of the exclusion list for next boot.

volumename

The volume name can be either a drive letter (for example, C), a device name (for example, \Device\Harddiskvolume), or a volume GUID path in the form of "\\?\Volume{GUID}\" where GUID is a globally unique identifier (GUID) that identifies the volume (for example, \\?\Volume{26a21bda-a627-11d7-9931-806e6f6e6963}\).

The ability to reference a volume using a volume GUID path is new to Windows Embedded Standard 7. Referencing volumes using GUIDs is more reliable because you avoid factors that make it difficult to identify a volume. For example, two volumes having the same label, a volume having no drive letter or label, and drive letters changing as volumes are added to and removed from the computer. For more information, see Naming a Volume. To retrieve the GUID volume path for a volume, see the GetVolumeNameForVolumeMountPoint Function.

Notice that the name is not the volume label that Windows Explorer displays before the drive letter.

addvolume

Adds a volume to the protected volume list for the next boot.

commit

Commits the changes that you made to the file to the underlying media.

The volume name can be either a drive letter (for example, C), a device name (for example, \Device\Harddiskvolume), or a volume GUID path in the form of "\\?\Volume{GUID}\" where GUID is a globally unique identifier (GUID) that identifies the volume (for example, \\?\Volume{26a21bda-a627-11d7-9931-806e6f6e6963}\).

The ability to reference a volume using a volume GUID path is new to Windows Embedded Standard 7. Referencing volumes using GUIDs is more reliable because you avoid factors that make it difficult to identify a volume. For example, two volumes having the same label, a volume having no drive letter or label, and drive letters changing as volumes are added to and removed from the computer. For more information, see Naming a Volume. To retrieve the GUID volume path for a volume, see the GetVolumeNameForVolumeMountPoint Function.

Notice that the volume must currently be protected. Otherwise, you receive the following error message: "The system cannot find the drive specified."

disable

Disables the write filter on the next restart.

displayconfig

Displays all configuration information for the write filter including a protected volumes list, the overlay configuration, and write-through paths. The command returns:

  • State - Indicates current filter state (enabled or disabled) and state for the next boot.
  • Protected Volumes - List of protected volumes including the current and the next boot state.
  • Compression - Current and next boot state for cache compression.
  • Threshold - Current and next boot values for the overlay cache threshold.
  • Write-Through Paths - Displays a complete list of active and next boot write-through paths.
  • Preallocation Status - Displays current and next boot status for cache preallocation.

enable

Enables the write filter on the next restart.

getactualsize

Displays the actual volume disk size information.

getvirtualsize

Displays the virtual volume disk size information.

help / [switch]

Displays help information for a specific FBWF Manager switch.

overlaydetail

Displays details on the current overlay contents for all protected volumes. The command returns:

  • Contents - Files and folders currently in the overlay for all protected volumes including sizes (size of data in overlay) and open file handles.
  • Memory Usage - Total amount of memory being consumed by the overlay.

removeexclusion

Removes a write-through path from the exclusion list for next boot.

The volume name can be either a drive letter (for example, C), a device name (for example, \Device\Harddiskvolume), or a volume GUID path in the form of "\\?\Volume{GUID}\" where GUID is a globally unique identifier (GUID) that identifies the volume (for example, \\?\Volume{26a21bda-a627-11d7-9931-806e6f6e6963}\).

The ability to reference a volume using a volume GUID path is new to Windows Embedded Standard 7. Referencing volumes using GUIDs is more reliable because you avoid factors that make it difficult to identify a volume. For example, two volumes having the same label, a volume having no drive letter or label, and drive letters changing as volumes are added to and removed from the computer. For more information, see Naming a Volume. To retrieve the GUID volume path for a volume, see the GetVolumeNameForVolumeMountPoint Function.

Notice that the name is not the volume label that Windows Explorer displays before the drive letter.

removevolume

Removes a volume from the protected volume list for next boot and either preserves the exclusion list (0) or removes it (1).

restore

Discards the changes that you made to the file, that is, restores the files to its original contents from the underlying media.

The volume name can be either a drive letter (for example, C), a device name (for example, \Device\Harddiskvolume), or a volume GUID path in the form of "\\?\Volume{GUID}\" where GUID is a globally unique identifier (GUID) that identifies the volume (for example, \\?\Volume{26a21bda-a627-11d7-9931-806e6f6e6963}\).

The ability to reference a volume using a volume GUID path is new to Windows Embedded Standard 7. Referencing volumes using GUIDs is more reliable because you avoid factors that make it difficult to identify a volume. For example, two volumes having the same label, a volume having no drive letter or label, and drive letters changing as volumes are added to and removed from the computer. For more information, see Naming a Volume. To retrieve the GUID volume path for a volume, see the GetVolumeNameForVolumeMountPoint Function.

Notice that the name is not the volume label that Windows Explorer displays before the drive letter.

It is acceptable that the file was deleted. In this case, it is recovered.

Notice that the volume must currently be protected. Otherwise, you receive the following error message "The system cannot find the drive specified."

setcompression

Sets overlay compression as enabled (1) or disabled (0) for the next boot.

setpreallocation

Sets cache pre-allocation as enabled (1) or disabled (0) for the next boot.

setsizedisplay

Sets the size display mode to either virtual (1) or actual (0). The new mode takes effect after the next restart.

setthreshold

Sets the overlay threshold value for the next boot. The input field threshold is the overlay threshold in MB.

If no switch is provided, the FBWF Manager displays all the configuration information, exactly as the displayConfig switch.

FBWF APIs are provided for comprehensive management and configuration of devices in the field.

FBWF does not resolve substituted paths. Use complete file names instead.

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