Yes but see my sibling comment. When you expand your array, your existing data will not be stored any more efficiently. To get the new parity/data ratios, you

Yes but see my sibling comment. When you expand your array, your existing data will not be stored any more efficiently. To get the new parity/data ratios, you would have to force copies of the data and delete the old, inefficient versions, e.g. with something like this [1] My personal take is that it's a much better idea to buy individual complete raid-z configurations and add new ones / replace old ones (disk by disk!) as you go. [1] https://github.com/markusressel/zfs-inplace-rebalancing https://github.com/markusressel/zfs-inplace-rebalancing