that is correct, VDEVs must be build identically to source devices.
I haven't been able to find an answer to this. I need to create vdev devices and pair them with R2 devices. The R2 devices are tdev meta's. In creating the vdev devices, do they have to be the same size/geometry as the R2 tdev device(s)? Ie: if the R2 is 960GB (4*240GB), do I create 4 vdev devices at 240GB and create a meta from them and then use that meta vdev to pair to the R2?  Thanks.
vdev sizing