Moving files from external SSD to iCloud for Mac Mini upgrade

You can not do that, because iCloud is not a backup for Mac's.

I think you mean that the external 2T SSD that has 1.4T used and about 530GB avalible.

The best move is to order the Mac mini with a 2T Storage Drive, so that it will hold everything.

Optionally you can setup the new 256GB or 500GB Mac mini using the same Apple ID.

Then connect the external 2T SSD to the new Mac mini and access your data that is on the 2T SSD.

With this setup you will not be able to migrate or sync in more than settings, passwords and contacts from iCloud.

Whatever you do, do not buy the new Mac with only a 256 GB drive. You will discover very quickly that capacity is woefully lacking. A startup drive with 500 GB is better, but 1 TB is the smallest startup drive I would ever recommend these days.

The only files that absolutely must remain on the boot drive are the OS files, obviously. That and the user's home folder. Any user documents normally homed within can generally be safely moved to the cloud.

I see no reason why you can't simply buy your new Mac with whatever capacity it has, and then upgrade the boot OS on the external drive to something compatible, i.e. Sequoia. Then you can continue to use that as your boot drive.

Gil Woolley wrote:

My downloads folder is 360 MB and includes vital banking information. Is it safe to move that to iCloud? Which types of files should I move to the cloud?

Do you have some sort of backup for this computer? Apple provides free backup software with macOS called Time Machine, but there are also third party options as well.

Back up your Mac with Time Machine - Apple Support

If you don't have a backup, then before you do anything else, you should make sure to have a good backup on some local storage media. As others have mentioned iCloud and other file syncing cloud services are not a backup. Why? If you make a catastrophic file edit or deletion, then every copy of that file is affected on every other device which is using that cloud file syncing service. Not really a backup is it?

FYI, there are a lot more new ways to permanently losing access to the data stored on the internal SSD of the recent Macs due to all of the hardware, software, and security changes. Without good backups (frequent & regular, with at least two backup copies) sooner or later you will end up losing some or all of your important files.

People should always have frequent and regular backups of their computer and all external media (including the cloud) which contains important & unique data.

Please check your capacities.

You have posted using MB and GB capacities, but you are likely actually looking at TB capacities, or at least capacities greater than 2 GB, 1.4 GB, 530 MB etc.

Clarification is needed.