On 2019-11-15 14:34, Rafael Possamai wrote:
My experience with ZFS (FreeNAS for the most part) is that it becomes more "expensive" to expand your pool after the fact (for a couple of different reasons, see below),
That's probably case with more complex ZFS RAID setup, but for this particular usage RAID1 should be fine (OP preferred AFAIK on backup box) and expanding ZFS RAID1 is a matter of few commands and hardware work. I expanded ZFS RAID1 from old SXDE I don't remember year, 160 GB -> 500 GB -> 1TB over the years. I used the same trick to even switch from hdd to ssd, 1TB -> 1TB. Basically the only thing you need is to put your new drive(s) into the system and attach (zfs attach!) it to mirror, wait for resilver and then detach (zfs detach!) the old drives. You can then detach drives physically form the box. Anyway once your mirror is built of bigger drives it expands automatically.