All the major NAS brands have a google cloud sync (synology/QNAP/asusstor/casaos)

Owncloud/Nextcloud have a google drive sync plugin

You could use something like rsync to copy to another cloud or drive.

1. You could add more with a usb/thunderbolt/sas jbod expansion.

2. Buy a bigger unit, transfer the drives and sell the old one

3. Clustering/hyperconverged with truenas or ceph

Something like this?

Obviously this is make for ripping DVD/Blu-Rays, but combined with software like Automatic Ripping Machine, I feel confident that you could automate 90% of this. (Still would need to put disks in, and rename any folders that were created).

Based on the fact that you are dealing with medical files, you likely have HIPPA hoops to jump through, so using a unmanaged second computer might be out of the question. (As an it administrator I would not allow a raspberry pi or similar access to the VPN/Network). You may have luck asking IT for a second computer (that they control), and then do the USB drive option.

Assuming you have unlimited power and noise tolerance

I would start with a used dell 720xd for $350 and then fill it up with drives. If you need more add jbods

CasaOS can mix and match, but it uses mergerFS which doesn’t have the same parity as ZFS/ceph/raid.

Im also a big fan of CasaOS and run it. You should also check out ZimaOS alpha release as it has more raid functionality.

ZFS needs roughly 1GB of ram per TB of storage.

Truenas code is older and runs on BSD. 99% of people will want to run Scale.

Unraid- if your drives are different sizes. Truenas - if you have lots of ram and like ZFS. CasaOs - If you like pretty things. Proxmox + Open Media Vault - If you want to run vms.

Completely False? No known 3.5 external that isn’t normal inside?

You sure about that?

What about these drives that have a USB interface instead of SATA.