File Based Write Filter (Fbwf) - Siemens SIMATIC IPC477E Operating Instructions Manual

5.5.3

File Based Write Filter (FBWF)

Purpose and function
With the Feature Pack 2007 for Windows XP Embedded Standard 7, 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.
SIMATIC IPC477E
Operating Instructions, 12/2016, A5E37455003-AB
CAUTION
Data loss with several write filters
Both EWF and FBWF are preinstalled in the SIMATIC IPC images. If several writer
filters are active on one partition at the same time, you may experience data loss. This
may damage the machine or plant.
Make sure that you only activate one write filter for each partition.
Operating the device and device functions
5.5 Extended device functions
73