How to safely upload large folders to iCloud Drive with limited Mac storage?

Question

How to safely upload large folders to iCloud Drive with limited Mac storage?

Hi everyone,

I recently upgraded to the 2TB iCloud plan. I am trying to back up about 1TB of files and folders stored across two external SSDs directly to iCloud. However, my Mac only has a 256GB internal SSD, which is causing severe storage bottlenecks.

What I did & What went wrong:

Because my internal drive is small, dragging large folders into iCloud Drive filled up my Mac's local staging/cache space, triggering a "Storage Full" error.
To work around this, I ran cache-clearing terminal commands, restarted my Mac, and copied 3–4 folders at a time. I repeated this tedious cycle until I successfully finished transferring all data from SSD 1.
Thinking everything was safely stored in iCloud, I turned off iCloud Drive sync and selected "Remove" to clear the local copies off my Mac.
The next day, when I plugged in SSD 2 and re-enabled iCloud Drive sync to start the second batch, macOS cleared/deleted the previously uploaded folders from iCloud. My hours of work were completely wiped out.

My Constraints & Questions:

iCloud.com in the web browser does not support uploading whole folder structures (only individual files). ( : Google drive support upload the entire folder structure)
I need a full copy of my folders in iCloud, but I cannot store them on my local 256GB drive.

What is the safest way to upload large folder hierarchies to iCloud without running out of local SSD space or risking accidental cloud deletion when toggling sync?
Is there a reliable way or tool to force macOS to offload local copies to the cloud immediately without turning off iCloud Drive entirely?
Or I better move to Google drive as iCloud creates more frustration.

Thanks for your help!

Posted on Sep 7, 2026 8:29 PM

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Answer 1

Sep 7, 2026 10:22 PM in response to rahuman_kamal

Beware that iCloud is NOT a backup but a sync service. So any mistake you make is synced to other devices. To backup, use Time Machine or 3rd party apps like Carbon Copy Cloner or Super Duper.

I'd recommend using an external APFS formatted (GUID, case insensitive) disk for large files, and backup that to another external disk.

You can clumsily offload local copies from the Mac by ctrl-clicking them on the iCloud Drive and choose "Remove Download". But that works only in 10 item batches, and might not offload all folder contents. And if you open such file, it is downloaded , and you must offload it again.

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Answer 2

Sep 8, 2026 8:57 AM in response to rahuman_kamal

You might want to consider booting off an external SSD. See this:

How to use an external storage device as a Mac startup disk - Apple Support

But Matti Haveri's warnings are relevant in any case:

#1 iCloud Drive is not designed to be a backup or to be handy for archiving files.These uses expect an unchanging environment! iCloud is for synchronizing files on several devices, and as such, it facilitates changing files.

#2 You can't move more than a few files at a time. (This is basically because of #1.)

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