iCloud Drive shows inconsistent disk usage while syncing to a second Mac

Question

Level 1

10 points

iCloud Drive shows inconsistent disk usage while syncing to a second Mac

I have an iMac with a 2 TB disk and iCloud Drive. Everything works correctly: sync is complete and the effective occupied space is about 805 GB.

Now I am setting up a second Mac, also with a 2 TB disk. It has been downloading and syncing for four days, but the values I see are very confusing:

Disk Info reports: 1.99 TB used
Folder Info (my main folder “SPLS”): 673 GB total, 1.79 TB on disk
On the first Mac, the same folder reports: 673 GB total, 673 GB on disk

So it looks like I am “losing” more than 1 TB on the second Mac.

Where has that space gone? Is this expected behavior during iCloud Drive sync, or is something wrong? (download is still running)

Thanks for any help

iMac 27″, macOS 26.0

Posted on Oct 2, 2025 1:22 AM

Reply

Answer 1

Top-ranking reply

gbecattini Author

Level 1

10 points

Oct 3, 2025 1:10 AM in response to gbecattini

SELF ANSWER

After completing a large iCloud Drive sync on Monterey, many files showed “on disk” sizes 10–20× larger than their logical size, and the volume was almost full.

This isn’t real duplication: it’s an APFS/FileProvider metadata artifact. A simple workaround is enough: make a plain Finder copy of the files or folders (ideally to a location outside iCloud Drive to avoid uploads). No edit or rewrite is required—the copy forces a full read, APFS revalidates block mappings, and both the copy and the originalimmediately report the correct “on disk” size.

Affinity apps add another wrinkle: their documents can embed change deltas, so sometimes a larger physical footprint than the logical size is legitimate.

In short: if you see huge “on disk” values after a big sync, it’s usually metadata. Copying the items normalizes usage; no real space was lost.

Reply