iCloud & iCloud Photos · iCloud Photos and the Photos library
Will moving my Photos library break iCloud Photos?
Short answer: It can if you move it outside Photos' own method — iCloud Photos follows only the System Photo Library. Storage Studio won't relocate it for that reason. Move it in Finder, open it in Photos, then choose Use as System Photo Library.
It can, if the library is moved any way other than Photos' own method. iCloud Photos only syncs the library Photos treats as the System Photo Library; a library copied or relocated behind Photos' back can leave iCloud Photos, Shared Albums and Memories pointed at the wrong one.
That's why Storage Studio won't relocate the library itself and says "Your photo library has to be moved from inside Photos, not from here." Moved Apple's way, iCloud Photos keeps working:
- Copy the library to the drive in Finder with Photos quit.
- Open it from Photos (hold Option at launch).
- Click Use as System Photo Library in Photos → Settings → General.
Full steps: moving the Photos library.