If iCloud Photo Library cannot be turned on again because of lack of Cloud storage after moving or restoring the Photos Library
Turning on iCloud Photo Library again can be a problem after moving the library to a new drive or restoring it from a backup. Even if the library is still identical to the library in iCloud, iCloud will upload it again to iCloud.
Whenever there is the least doubt that the library you are trying to enable for iCloud may changed slightly, Photos will upload the complete library to compare it to iCloud, after restoring from a backup or moving the library to a different drive, or after repairing the library, even after turning iCloud Photo Library off and on again (Why is iCloud uploading my entire iCloud Photo library again after I moved its location?). The restored library from a backup may contain photos that already have been deleted from iCloud, or may have different edits and metadata applied.
When Photos estimates the amount of iCloud storage needed for the additional upload, it will estimate the required storage using the worst case assumption that all photos are different. If there is not enough free iCloud storage to upload the complete library again in addition to the photos already in iCloud, Photos will not allow you to enable iCloud Photo Library.
You have now two options:
- Sign up for more iCloud storage for a month, so you can start the upload, then cancel the additional storage again.
- Or create a new, empty Photos Library and download the library from iCloud to your Mac. This will not require additional cloud storage, since the library is empty. This will work, if you did not import any new photos since the last sync with iCloud.
I prefer to download the library from iCloud to a new, empty library instead of uploading the restored library. This method cannot restore the projects, but you can save your projects by keeping a copy of your current library on a external drive. Downloading to an empty library has the added advantage that it will be faster than uploading and merging into the existing library, and it will rebuild your library.
My library has 50000 photos and videos.
- When I upload it again, it needs roughly ten days for merging into the iCloud library.
- When I only download to the empty library, downloading an optimized version will be done in half a day, and downloading all originals as well will be done in five days, much faster.
To create a new, empty library launch Photos while holding down the options key ⌥. Keep holding down the key until the library chooser panel appears.
Photos 3.0 on macOS 10.13 High Sierra (and the newer versions) is syncing the named faces to iCloud, so downloading the library from iCloud will also restore the People album with the named faces. This document describes, what will sync from your Mac to iCloud on High Sierra: Use Photos and iCloud Photos on multiple Mac Computers
For older versions of Photos the named faces will be lost in addition to the projects. Then it might be preferable to upload the library again and to pay for additional cloud storage for a month.
This user tip was generated from the following discussion: how do i turn on iCloud Photos back on after restore?