Data Domin: any way to add 5 drives in an exisiting RAID6 array?

I have DD6620 with 7x1TB drives, 1 hot spare, and 6 in RAID6. Now, I am going to add 5 new 1TB drives. Are there any ways to add new drives in existing RAID, or I have to create a new RAID6?

Thanks for your inputs.