A700s and MetroCluster

Hi all!

I need understand how to move root aggregates in Ontap 9.1 to new aggregate in metrocluster.

I have four nodes AFF700 with 3,8TB disks...

To metrocluster root volumes, I use 16 disks (4 aggregates in raid 4 replicated and two pools... This is bad... Need replicated all root aggregate, sure? Or not need replicated?)...A lot of area used for root aggregate...

If add new shelf (one shelf in each sites) with disks smaller sizes, would it be possible to move root vols to these disks?

Read kb below.. Ontap 9.0 introduced "system node migrate-root"... This works in metrocluster?

https://kb.netapp.com/support/s/article/ka31A000000CqHFQA0/How-to-non-disruptively-create-a-new-root-aggregate-and-have-it-host-the-root-volume-in-clustered-Data-ONTAP-8-2-and-8-3-ONTAP-9-0?language=en_US

Thanks for your atention!