@GP81.....
I don't think 'raidctl' will work on a T4-1. Raidctl is for the older built-in LSI hardware raid controllers used on hardware like the T2000.
If it was a LSI like that, then as Bartus11 says, once a raid mirror is configured the mirror drive is 'hidden' from view.
This is a T4-1 which uses a different raid controller and different command set.......
Create a Hardware RAID Volume - SPARC T4-1 Server HTML Document Collection
I've already made the point that typical factory configurations have the first two slots mirrored when supplied to the customer and this appears to be what we've got here.
We've got to the point where several members are trying to help and speculating over the resolution of the problem but what we need is Kerrygold to post more output.
I agree with Bartus11 that we all wait for Kerrygold to get back online otherwise we are all just guessing.
My own experience with T4 series is pretty thin anyway.