thank you very much. Save and recopy OPEN data is no problem. The problem are the hidden data possibly in divers repertories as /etc , /usr/share and, of course, /home/jef . For ex. I did not find some content for certain app's in /home/jef/.config/somewhat/... . The subdir's somewhat exist but are empty. What is the recommended approach to back up the own personal data just bevor doing refractasnapshot alt. the actualization of the entire system, some kind also of refractasnapshot restricted of the usual and typical own personal data (/etc/alternatives , /etc/grub.d , /usr/share/some_growing_subdir's , /var/some_growing_subdir's possibly containing kind of user' s data, and of course hidden data in /home/jef/ like /home/jef/.config , /home/jef/.mozilla for those using mozilla, etc. if other typical other subdir's contain usually data changed yesterday (I don't speak from very special needs for those installing very special software: they are aware about that, I hope)? Are changes recommended in the settings of the common refractasnapshot? Can then the refractasnapshot be used for that second wave for the own data with other adapted / also special settings to save the own user's data immediately before I start with an important system actualization where I can not appreciate in which condition my system will be after that. Refractasnapshot is so fast and secure, it would be a great tool for that. My OPEN data are all (including /home/jef/Downloads through a link instead of the subdir ~/Download itself in a separate partition mounted in /home/stef/0 through /etc/fstab by start so that I have nothing else to do at actualization time as umount /home/stef/0. They come so never into the snapshot (and would not be possible: the partition is about 1 TB big!)