User tmkoeln describes in bug 10251 that the vnstat data isn't saved. My investigation showed that there is general bug in backup.pl, which doesn't save a bunch of directories. Browsing through git showed that this bug is introduced years ago. Therefore my question: Are there other "strange" issues with backup/restore?
If I fix this known bug it would help knowing about other abnormalities. ;)
A workaround for the moment is posted in bugzilla.
Regards Bernhard