Moxa DA-681A-I-DPP-LX [19/42] File based write filter

DA-681A Series Windows Software Enabling Embedded Filters

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3. Once the EWF control dialog is open, select the drive you wish to operate on from the upper window of the

dialog, and then click on the Pending Command drop-down menu below. There are four choices:

No Command

Disable: Disables EWF on the selected drive. Be aware that the system will automatically reboot if you

select this command.

Commit: Writes all current changes to the system data to the hard drive.

Commit and Disable Live: Writes all current data and changes to the system, and also turns off EWF on

the selected drive (so that all future data and system changes will also be committed to the drive, as well).

Selecting this option will NOT automatically reboot your system.

For more detailed descriptions of these commands, please refer to the Microsoft website shown below:

http://msdn.microsoft.com/en-us/library/ff794092(v=winembedded.60).aspx

File-Based Write Filter

Overview

This section describes how to use the File-Based Writer Filter (FBWF). Note that when Enhanced Writer Filter is

enabled, the File-Based Writer Filter function will not work.

According to Microsoft:

“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.”

FBWF supports an advanced ESF feature, which allows users to specify which directory to write data to. The

default directory is c:\temp. The advanced feature allows you can read/write data to disk without committing

an action.