Rebuilding a Photos Library by downloading a new copy from iCloud
If a Photos Library should become badly damaged, for example by being stored on a failing drive, and even the built-in Library repair tool cannot fix the library (How to use the Photos library repair tool - Apple Support), we can rebuild the library by downloading it from iCloud to a new, empty library.
If you are sure, that all photos and videos are already in iCloud, try this:
- Simply make a backup copy of your Photos Library on an external volume, just in case something should go wrong.
- Then delete your Photos Library.photoslibrary from your Pictures folder (or wherever you are keeping your Photos Library).
- Now create a new, empty Photos Library. (see: Create additional libraries)
If the Photos appon your Mac is open, choose Photos > Quit Photos.
1. Hold down the Option key and double-click the Photos icon in the Applications folder (or click the Photos icon in the Dock) to open Photos.
2. In the Choose Library dialogue, click Create New.
3. Type a library name and choose a location to store the library.
4.Click OK.
- Make this new library your System Photo Library in the Photos Preferences > General, see System Photo Library overview.
1.In the Photos app
2.To make the current library the System Photo Library, click Use as System Photo Library.
- then make it the iCloud Photos Library in the Photos > Preferences > iCloud and enable immediately Optimize Storage for a speedy download.
Photos will now download your iCloud Photos to the new library and this new library will initially be very small and only have optimised versions. You can later switch to "Download Originals" if you prefer to have the originals stored locally. .
There is one drawback: The projects will be missing, because iCloud is not storing the projects. And some named faces may be missing. Photos is storing all named faces in iCloud, but I frequently found that manually added faces circles have not been restored from iCloud. So it is essential to keep an archive copy of your Photos Library, before you let iCloud optimise it. You need a local copy anyway, because it is hard to backup an optimised iCloud Library. A local copy is easier to backup.
You can use the same method to migrate your Photos Library to a new computer.