I think buying a larger drive would indeed be the safest option.

Yeah exactly, I think I’ll just upgrade the 1TB drive.

That would indeed solve the problem. Although I’m a bit hesitant as I do like the peace of mind when having an additional copy. Otherwise I only have two real copies of my data.

I guess as the two drives are in a zfs mirror, restoring could still be done locally without pulling data from blackblaze. If I want to revert my data back to a previous state, I can’t do it with a local copy, so I would have to pull quite some data from blackblaze.

If you’re looking for just filesharing capabilities, OwnCloud might be a good alternative. It’s recently been rewritten in Go and its supposedly quite fast. I must say that I haven’t used it myself.

Another alternative could be Nextcloud, but that comes with a whole suite of other software such as calendar, contacts, …

I’ve also heard some good things about seafile, but never used it myself either.