Solaris ZFS question

What I am trying to do is reuse space that was used from an old solaris zone and take that space used in the 2 disk mirror from the 2nd zpool and relocate it to /var/audit in the root pool. The pysical server has 4 disks. 2 disks are a mirrored root zone(c1t0d0s0,c1t1d0s0) and the other were the mirrored pool(c1t2d0s0,c1t3d0s0) that the zone ran off of.

I have been able to succesfully remove the remove and uninstall the solaris zone. I am now trying to add these two disks c1t2d0s0 and c1t3d0s0. These partitions use a slice that is the whole disk.

I have tried to add the 2 reclaimed disks to the root pool mirror with "zpool add rootpool mirror c1t2d0s0 c1t3d0s0" and also by adding -f. This give me the error:

cannot add to 'rootpool': root pool can not have multiple vdevs or seperate logs.

What am I missing? I though I could add the 2 disks to the rootpool mirror. Then I wanted to somehow grow the rootpool/audit filesystem to include the new disk space.

You need to create a whole new root pool and use beadm. You cannot add devices to an existing root pool mirror.

Here is how:
Managing Your ZFS Root Pool - Oracle Solaris 11.1 Administration: ZFS File Systems