Create 4TB RAID volumes during install?

[CS_DBA]

Hi All;

I have a server which we've setup with 2 - 500GB drives and 6 -  4TB drives
I want to mirror the 2 500GB drives as a RAID 1 volume - works as expected

However I also want to add all 6 4TB drives to a single RAID 10 RAID device

I try and create a raid volume, choose one of the 4TB drives and it wont 
let me select more than 2TB of space.  Can someone give some insight on 
how to pull this off?

Thanks in advance