2 metadb replicas created when adding a disk to a metaset?

Hi Gurus,

A colleague was building new cluster (Solaris 10u10 , SC 3.3u2) and when adding a number of disks to a metaset he noticed that after  25 disks it stopped adding metadbs to the disk. I looked at the problem and realised that every disk:was being added with two dbase replicas, so he had hit the 50 replica limit.

I have two questions:-

Why was 2 dbase replicas being created for each metaset -s xxxx /dev/did/dsk/dy command? I have never seen this behaviour before and another metaset on the same server had created only 1 metadb per device (which I believe is normal)