In general, virtual disk arrays tend to load disks evenly. However, it is worth using dkconfig(ADM) to check that the read and write counts to each of an array's pieces are even. If they are not, try changing the cluster size or the number of pieces in the array.
If a physical disk is a member of more then one array,
use sar -d to check that the
disks are being used evenly as described in
``Viewing disk and other block I/O activity''.
If the load is unbalanced, try rearranging the disks between the arrays.