After a few years of trial and error, this is my setup / workflow:
On a higher level:
- One 12Tb HDD on local PC holds the photo's folder (see below, with 3 subfolders). This HDD gets replaced every 4 yrs.
- This folder gets backupped (one way mirror via Pure Sync) to a Synology NAS where the backupped immediate gets a 2nd copy to a 2n HDD (this means I have 3 copies in my possession: one on the local machine, 2 on the NAS).
- This NAS gets periodically backupped (grandfather-father-son) via Synology Hyper Backup to cheap cold Google Cloud Storage "in case of disaster". The NAS HDD's are replaced every 5 yr.
- The albums folders (only 500Gb) gets mirrored periodically to a cloud service (in case One Drive) via Synology Cloud Sync (also a second "in case of really big disaster")
On a lower level:
- The 12Tb HDD holds:
A. a decharging folder in which all pictures post 2020 reside on a year/month/day basis
(these pictures go into collections via Light room, so no subfolder stuff necessary here)
B. a folder with subfolders per holiday / event / shooting session for everything pre 2020
C. an albums folder with a few hundred subfolders with lighter JPEG exports in it (holds let's say "the finished product")
I work in Lightroom where all pictures are accompanied with ther XML file, so in case of disaster (Lightroom settings lost), at least the work I have done on one specific file can be recovered