Functions
9.3 File Based Write Filter (FBWF)
SIMATIC IPC427C
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Operating Instructions, 04/2009, A5E02414743-01
9.3
File Based Write Filter (FBWF)
Purpose and function
With the Feature Pack 2007 for Windows XP Embedded, Microsoft introduced a second
write filter, File Based Write Filter (FBWF).
In contrast to EWF, which protects partitions based on sectors, FBWF works on the file level.
When FBWF is enabled, all files and folders of a partition are protected unless they are
included in an exception list.
FBWF is disabled by factory default in the operating system images for SIMATIC IPC and
must be enabled and configured by the user.
When you enable FBWF, the folders C:\FBWF and D:\FBWF are authorized for writing by
default.
Comparison between EWF and FBWF
●
You should prefer FBWF, because it is more flexible in its configuration and allows
immediate writing without rebooting.
●
If you use HORM or compressed NTFS, EWF is indispensable.
CAUTION
Activate only one write filter per partition - otherwise you may incur data loss.
Both EWF and FBWF are preinstalled in the SIMATIC IPC images.
Ensure that only one write filter is enabled on a partition, otherwise you may incur data
loss.
Configuring FBWF
FBWF can be configured in command console using the program FBWFMGR.EXE.
NOTICE
•
Observe the following syntax: Enter a space after the drive designation colon.
•
Changes for direct write access only take effect after rebooting.
•
Only existing files and folders can be entered in the exception list.
