EWF and File Based Write Filtering (FBWF) (Windows Embedded Standard 2009)
4/23/2012
Windows Embedded Standard provides two write filters: FBWF, which operates at the file level, and Enhanced Write Filter (EWF), which operates at the sector level.
In most cases, you use FBWF; however, to support NTFS fully, you must use EWF.
EWF supports the following NTFS features that are not supported in FBWF:
- File locking and unlocking
- File ID in NTFS
- Reparse points
- Quota
- Hard links
- Opportunistic lock
- File compression and encryption
In addition, to use Hibernate Once Resume Many (HORM) you must choose EWF.
EWF also provides the following functions that are not providded in FBWF:
- Support for multiple overlays
- Support for disk overlays
- Live commit and disable
To use EWF and FWBF together in the same OS image, enable EWF on one volume and FBWF on another volume.
Note
The Windows Embedded Standard installer installs all files relating to EWF and FBWF in the EWFAPI directory and FBWFAPI directory at %Program Files%\Windows Embedded.