Hello Kjell,
Thanks for your time analyzing and explaining my backup strategy and proposing yours.
You wrote that my strategy wont work. Maybe i'm missing something or I explained wrong.
As I understood your strategy is based on annually full backups (N=0) and maybe you understood that my approach is the same.
My intention is that after new year N is again incremented to 13 and NOT starting over again from 0.
So after two years N=24 with 24 files. First file is the full backup and the other files contains one month of data.
Note that I replace the daily N file with the new one.
This way (with understanding of how nbackup works), I avoid to ever having to do a full backup more than once.
Whats your thoughts on this?

BR,
Hugo