Server 2012 Core (no GUI) - How to manage disks?
You probably want to use the diskpart.exe tool.
c:\diskpart
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 60 GB 0 B
Disk 1 Online 200 GB 200 GB
DISKPART> select disk 1
Disk 1 is now the selected disk.
DISKPART> create partition primary
DISKPART> list partition
DISKPART> select partition 1
DISKPART> format fs=NTFS quick
DISKPART> assign letter=D
See http://technet.microsoft.com/en-us/library/cc770877.aspx