I always wondered why backups of my sever using duplicity are so huge, but simply looking at list of files to include seemed to be correct. However I should really spend more time by reading documentation, because now it was obvious to me that the file list is simply wrong.
What a small difference in file list:
- /var/lib/vservers/ + /var/lib
Versus the old one:
+ /var/lib - /var/lib/vservers/