Ah, OK.

Yea, not sure if these units can yet support expansion of a data set.

BTRFS and ZFS technically have the capability (from what I recall) in the latest versions, the question is does the device you’re looking at support the capability? I haven’t looked into enough of them to know for sure.

That said, my ancient Drobo can do this, but… It will only see the new size once you upgrade all the drives. It will resilver with a new larger drive but until all drives are upgraded it won’t use the extra drive space of an added larger drive.

(And yes, Drobo is garbage, this one was free, I had some spare drives and I use it as a third local storage device, kind of a spare I don’t really trust).