Where is photos.sqlite-shm I am trying to sync my Mac (macOS 11.2.3) &quot;Pictures&quot; 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!
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.