Photos not synching, macOS 'optimize storage' not working, and 175GB of photos downloaded for no reason

Question

Suddenly, my Mac stopped synching my photos:

I have tons of free space on iCloud, and optimize storage is turned on: There's no way that photos should take up 170 GB of space when there's only 250 GB in total of photos on iCloud: I have tried:

• Turning this function on and off in Photos.app
• Rebooting apps and the device
• Using all available options in the 'manage storage' dialog
• Turning off synching entirely: System Preferences > Internet Accounts > iCloud > Photos (uncheck) > Delete from my device

What else can I try to fix this bug?

Running the latest version of macOS.

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Update: Super buggy. I tried turning off iCloud completely, and now get this — 170GB of undeletable "Other" photos stuck on my Mac: I expected more paying for a premium MacBook Pro and $120 a year of iCloud synching. Do I need to take extreme measures and reinstall macOS completely?

Answer 1

The only thing that worked here was:

• turning off all synching and iCloud features,
• deleting all Photos.app files from my hard drive,
• and then starting with a fresh library.

Answer 2

There’s no reason to take extreme measures.

1. When was the last backup?
2. Set up Time Machine if you have no backup, exclude system files, it only backs up live data and not snapshots.
3. Make a new user account and give it admin.
4. Turn off automatic log in and reboot.

Now you can use the new admin account to examine if pruning local snapshots clears all the data. If not, delete your old user account (it’s safely backed up) and repeat cleaning snapshots. Only then would I consider an erase install if the storage allocation doesn’t make sense.

To get control of iCloud, you can restore your user account from backup while the internet is disabled, then disable cloud sync and learn why full automatic didn’t give you the results you expected. Nothing seems fundamentally wrong other than perhaps not considering APFS snapshots and needing to gather some info on how much photo data is actually reported as being in the cloud.