Many thanks!!!
Talking about the security you could encrypt the data, even if this would have some impact on the overall performance of the system.
19.7 UFS Journaling Through GEOM:
"Unlike other file system journaling implementations, the gjournal method is block based and not implemented as part of the file system - only as a GEOM extension."
Now i understand the importance of a file system journaling based on GEOM extension.