You cannot reduce aggregate nor can you destroy root aggregate - you will need to reinstall filer.
You may be able convert raid_dp aggregate to raid4, this gives you additional spare disk to create new root aggregate. Old aggregate will be destroyed anyway, so it does not matter. Or you can reassign spare from m other controller.
We only have one spare on the SATA shelf. So look like we will have to blow away the Aggr on SATA that includes Vol0 - (snapmirrored this across to the SAS shelf)
Recreate the SATA Aggr leaving 4 disks available.
Assign the 4 disks to the SAS controller.
Move the snapmirroed volumes back to the new Aggr on SATA.
Make another aggr with the 4 disks for the SAS controller.
Move the Vol0 for SAS to that aggr - Set As Root.
Blow away the SAS aggr and remove disk ownderships.
Remove the SAS shelf.
The question we had was will the SATA conroller run when we blow away the aggr to free up disks? The Vol0 for this controller is located in this location. We will copy it back after the new aggr is created.
I am hoping that only after a reboot that the changes would be seen.
Also using 4 disks is that overkill for just an aggr for Vol0?
If all SATA disks are owned by the other controller, that is not possible. You cannot relocate root disk to aggregate owned by another controller. You need free SATA disks to create aggregate owned by controller with SAS disks and then relocate root volume to this aggregate.
You may be able to change disk ownership of spare disks if you have enough of them.