Question: Is it safe to take a backup of just the newer Photos.app library, or may it have some crazy dependencies into the older iPhotos library?
On my 479 GB HDD,
348 GB is used by "iPhoto Library.migratedphotolibrary" and
356 GB is used by "Photos Library.photoslibrary".
That's 146 % of the total capacity, which confused me until I saw this post about hard linking. Before I discovered this I tried to take a backup of both libraries (using
rsync -var) onto a disk that should have enough capacity, but then rsync reported that the target disk wasn't big enough anyway. Assumedly rsync duplicates the files. So, can I safely skip backing up the older iPhoto library?