to create a partition greater than 2TB you need to use Parted.

Example of 4TB disk setup - 23 Sept 2013

# fdisk -l /dev/sdc
# parted /dev/sdc
(parted) mklabel gpt
Warning: The existing disk label on /dev/sdb will be destroyed 
and all data on this disk will be lost. Do you want to continue?
Yes/No? yes
(parted) unit TB
(parted) mkpart primary 0.00TB 4.00TB
(parted) print
(parted) quit

# mkfs.ext4 /dev/sdc1
# mkdir /4TB
# mount /dev/sdc1 /4TB
# df -h
# cp -rp /home/someuser/2TB/bigbunchoffiles /4TB/


more details and examples found at this website - the examples have two options:
	http://www.cyberciti.biz/tips/fdisk-unable-to-create-partition-greater-2tb.html