Moxa DA-682A-C7-W7E [13/53] File based write filter

DA-682A Win7 Software Enabling Windows 7 Write Protections

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File-Based Write Filter

Overview

File-Based Write Filter (FBWF) is similar to EWF, but is enforced at the file level rather than at the hardware

(bit) level. This means it is slightly less secure, but this allows it to provide more user features than is possible

with EWF.

File-Based Write Filter (FBWF) allows the Windows Embedded platform to maintain the

appearance of read and write access on write-sensitive or read-only storage. FBWF

makes read and write access transparent to applications.

Writing to storage media may be undesirable or impossible in embedded devices. FBWF

redirects all writes targeted for protected volumes to a RAM cache called an overlay. Used

in this context, an overlay is similar to a transparency overlay on an overhead projector.

Any change made to the overlay affects the picture as seen in the aggregate, but if the

overlay is removed, the underlying picture remains unchanged.

One of FBWF’s more advanced features allows the user to specify a directory where data may be more

conveniently written to the data drive than is possible with EWF. The DA-682A’s default settings have already

configured a default directory for this; you may use the c:\temp directory for files which require write access.

Enabling File-Based Write Filter

To enable file-based write filtering, do the following:

1. To verify that Enhanced Write Filter is disabled, type C:\...\>fbwfmgr /displayconfig to check the

current status.

2. Type fbwfmgr /enable to enable the FBWF, and then reboot the system to take effect.