MacBook disk space problem

Where is the Lightroom Classic catalog stored, inside or outside of the iCloud folder?

Also, how do you have the option set that’s shown in the picture below? Is Optimize Mac Storage enabled or disabled?

When you add images to a Lightroom Classic catalog from a camera card, two things happen: The images are copied to the folder you specified in the Destinations panel, and, if previews are set to be created, then those previews are created in the same folder as the Lightroom Classic catalog. So, those are two variables. The third variable is how iCloud is set in the picture above. If you can describe how you have those three things set up, we might be better able to answer the question.

For example, if the Lightroom Classic catalog is not in iCloud, the previews will be created on the Mac, using up space. But for 400 images, those previews should not use up all available space. Which is why I asked my last question in my earlier reply that you haven’t answered yet: 

How much free space is available on the Mac internal storage, before importing?

Lightroom Classic and Local Storage:

When you import photos into Lightroom Classic, the software copies them to a local folder on your computer’s hard drive before uploading them to the cloud.

These cached images remain on your local drive, taking up space without notifying you1.

Lightroom Classic requires all images to be stored on local drives (internal or external) or on a network drive. However, they don’t need to be in a single location; you can move older photos to an external drive that isn’t always connected to your computer2.

iCloud and Lightroom Classic:

Lightroom Classic cannot directly work with photos in the cloud (such as iCloud).

The reason for this restriction lies in the cloud’s inherent limitations:

Speed and Latency: Cloud storage is slower and has higher latency compared to local drives. Cloud providers cache files locally and sync them in the background, creating an illusion of immediacy. However, Lightroom still relies on local copies, which can consume space2.

Local Copies: Services like Dropbox, iCloud, Amazon Drive, and Google Drive create local copies of files, which doesn’t solve your MacBook’s space issue2.

Mountable Network Drives: Some providers offer mountable internet-based network drives, but expect them to be incredibly slow2.

Optimizing Your Workflow:

To avoid filling up your MacBook’s drive, consider these steps:

Configure Lightroom Cache: Set up your Lightroom cache so it doesn’t overwhelm your drive. You can adjust cache settings in Lightroom preferences.

Use External Drives: If you have an external drive, consider moving older photos there to free up space on your MacBook.

Choose “Download and Keep Originals”: If you’re using iCloud, ensure that the “Download and Keep Originals” option is selected under iCloud Photos settings3.

Directly Upload to iCloud: Since copying directly from the SD card to iCloud was faster, you might want to continue doing that for efficiency.

I’ll think about the iCloud workflow a little more since it is not typical, but one thing is for sure: Importing only 400 camera photos should not use up all remaining space on a Mac. That should be true regardless of the software or services used, from any company.

The only way it should happen is if the amount of free space is extremely low at the time of import. How much free space is available on the Mac internal storage, before importing?

Lr-Classic can only use image files if they are stored 'locally' on a hard-drive (SSD or Spin).

Lr-Classic cannot work with images stored only in iCloud.

I don't use a Mac so do not understand the workings of iCloud and 'local storage'.