iCloud Drive or music creation (or both?)

Question

So I'm trying to clean my Macbook Pro in order to have more storage, but this whole iCloud Drive thing is very confusing. Out of my total 121GB, 47GB are iCloud Drive and 22GB are music creation.

My question is whether my music creation files, many of which are stored in iCloud, are taking up space twice? My music creation storage consists of 19GB of Logic Pro projects (7GB on disk) and 16GB of Audacity projects (at least I believe the Audacity projects register as music creation). Beyond the music creation files I don't really have many files on here, so I'm having a hard time understanding where 47GB of iCloud Drive files are coming from. Is some of that space being taken up by duplicates of my music creation files?

Answer 1

If you go to Sytem Preferences/iCloud you'll see an option button as shown below.

Click on the options button and you'll get a new pane. At the bottom of this pane is a checkbox to optimize Mac storage. See the figure below.

This option can effect the free space on your hard drive. read the description next to the checkbox to determine which setting you want.

Answer 2

I presume you're looking at the page displayed when you go to Apple menu->About this Mac->Storage->Manage...

The number shown as "iCloud Drive" is the amount of space that duplicates what you have stored in iCloud. This is a very confusing number since macOS controls how much of your iCloud data is retained on your local disk. macOS will keep local copies of files you frequently access in a "cache"; this allows you to access them quickly without waiting for them to be downloaded. If your disk begins to get full, it will silently remove files from the cache, which is okay because you already have them in iCloud.

I hate saying things like this, but consider it to be behind-the-scenes magic.

Most likely you have a "cache" copy of most of your iCloud on your local disk, but the OS will manage it for you. It's unfortunate that (a) Apple doesn't allow much control of what gets cached and (b) some applications hide what's cached while others show it.

Once you've enabled iCloud Drive, it becomes difficult to tell how much free space you actually have. You may even get a warning that you're almost out of space, only to come back an hour later and find that hundreds of megabytes have suddenly become available...because the cache was pruned and/or files were pushed into your iCloud storage.