[rancor]

Nope, you're right on the money. My first thought was "this guy needs more VDEVs". Given the hardware and use case, 4x 6 disk RAIDZ2 VDEVs would make a ton more sense, and could also be cross-cabled to allow a controller failure.

[storrgie]

Smaller VDEVs make it a bit easier to increase size if you're rolling your own system. Buying 6 more drives instead of 8 or 10 is a smaller cost.