Or btrfs. I also think that filesystem snapshots are underrated backup strategy, assuming your data fits on one disk (which should be the case for almost all applications outside of FAANG).
Why would btrfs or btrfs snapshot require single disks?
My btrfs is combination of different size disks bought over time (3T to 24T) and snapshots works just fine. I've configured it to use raid with 2 copies for data and 3 for metadata.