Moxa V2416-T-XPE [13/45] V2416 w7e moxa software package

V2416 / W7E Moxa Software Package

3-2

Enhanced Write Filter

Overview

Enhanced Write Filter (EWF) provides a means for protecting a volume from writes. This allows the operating

system (OS) to boot from write-protected hard disks. All writes to an EWF-protected volume. (The Hard Disk

in the figure below) are redirected to an overlay(EWF Volume in the figure below). Because EWF does not write

data to hard disk directly, so it can protect the hard disk from sudden power loose. These writes are cached in

the overlay and made available as part of the volume. This gives the appearance that the volume is writeable.

The overlay is an independent storage location which exists in random access memory (RAM). If desired, the

data stored in the overlay may be committed to the protected volume. Refer to the following figure for the

overview of the EWF structure.

To get more details about EWF configuration and usage, you may:

• Visit Microsoft’s EWF Volume Configuration

help pages.

• Visit Microsoft’s EWF overview on the official Microsoft EWF help pages.

• Visit Microsoft’s detailed description of EWF modes on the EWF help pages.

• Visit Microsoft’s detailed description of the EWF API.

For the EWF commands, refer to the MSDN web site:

http://msdn.microsoft.com/en-us/library/ms940853%28v=winembedded.5%29.aspx