Where is photos.sqlite-shm

I am trying to sync my Mac (macOS 11.2.3) "Pictures" folder with my NAS using Synology Drive. I receive an error message stating that photos.sqlite-shm cannot be synced due to missing access rights or because the file is in use.

However, I cannot even find this file. What is it and where is it? It sounds like it has something to do with iOS. Thank you!

Solution 1:

If the Photos app is open on your Mac it opens photos.sqlite-shm. You can see what files Photos has open using Activity monitor. For me it is ~/Pictures/Photos Library.photoslibrary/database/Photos.sqlite-shm

Thus your sync process is correctly saying that the file is in use

Your process thus has to make sure that Photos.app is not running.