Nope, this can't be done. You could create a second VD across the same set of disks, but ONLY if all disks in the disk group has the space available, and the type (RAID 1, 5, etc.) must match: two RAID 1's, 4 RAID 1's, 2 RAID 5's, 3 RAID 5's, etc.
I have a PERC 6/i controller with the following disks sizes attached in this order 146, 146, 146, 146, 600, 300 GB.  I was hoping to create a RAID 5 set across the first 5 disks and then use the remaining space on the 5th disk along with the 6th disk to create a RAID1 mirror.  Is this possible?  I tried and the PERC firmware shows that there's no remaining space on the 600 GB drive as soon as I include it in the RAID5 with the other drives.  I'm wondering if I did something wrong and there's another way to configure it so that it works. Thanks.
Two different RAID Virtual Disks across same physical disks