Solaris Mirroring/Hotspare Issue

Hi Guys,
I have an issue with my Hotspares/Metastat on an x4270m2.
I have no hotspares available, when i printed out my metastat i got

d21: Concat/Stripe
    Size: 33559785 blocks (16 GB)
    Stripe 0:
        Device                             Start Block  Dbase   Reloc
        /dev/dsk/c0t5000CCA0258B3915d0s1          0     No      Yes

d20: Concat/Stripe
    Size: 551495385 blocks (262 GB)
    Stripe 0:
        Device                             Start Block  Dbase   Reloc
        /dev/dsk/c0t5000CCA0258B3915d0s0          0     No      Yes

so I'm also shy 2 submirrors as these are not attached.

I tried to attach them and got the following error:

root@tbair1>metattach d31 /dev/dsk/c0t5000CCA0258B3915d0
metattach: tbair1: c0t5000CCA0258B3915d0: not a metadevice

root@tbair1>metattach d31 d21
metattach: tbair1: d21: submirror too small to attach

So I tried to clear the device and recreate it but i got this:

root@tbair1>metadb -a -c 2 /dev/dsk/c0t5000CCA0258B3915d0s7
metadb: tbair1: c0t5000CCA0258B3915d0s7: has a metadevice database replica

and

root@tbair1>metainit d21 1 1 /dev/dsk/c0t5000CCA0258B3915d0s7 -h hsp002
metainit: tbair1: hsp002: invalid hotspare pool

Now all reference to d21 and d20 have disappeared from my metastat - which is to be expected i suppose as I detached/cleared them. My problem now it how do I reattach them and create my hotspares?

Thanks.