Sysadmin

You’re missing the point. For most residential deployments, which appears to be the use case here in this thread, it is not viable to expect deployments pre configured with the intended final/stable quantity of drives. Say someone deploys 6 drives today, a sizeable commitment for most residential deployments, for a RAIDZ2 deployment, they cannot later down the line add 2 more, and then 2 more without affecting the overall redundancy (data on the new 2/2 drives will either have no redundancy or 1:1 redundancy in their own vdevs). Lets also not pretend everyone will easily have a spare cluster sitting around to house all current data while they’re rebuilding the cluster for expansion. This inability to linearly expand as compared to more conventional md raid (or even hardware raid assuming if you have enough ports), where the lowest denomination in expansion is 1 drive at a time, any given time, basically eliminates it as a suitable candidate for most residential usage, as vast majority of residential users will not be expanding their raid in quantities of 6, 8, or 10 drives — and even if they do, vast majority wouldn’t want to take the extra hit on “sacrificing” more drives to parity. All that are things that are perfectly normal and expected in the enterprise space, but not residential.

And yes, the article I’ve linked has multiple updates which covers what is happening now. It’s not a stagnant outdated article. I’m well aware they’re intending to merge the vdev expansion PR, sometime this year, for the last I don’t even know how many years. I’ll re-evaluate ZFS when it is merged and appropriately battle tested in the wild.