To create a partition start GNU parted as follows:

parted /dev/sdb

Creates a new GPT disklabel i.e. partition table:

(parted) mklabel gpt

Next, set the default unit to TB, enter:

(parted) unit TB

To create a 3TB partition size, enter:

(parted) mkpart primary 0 0

OR

(parted) mkpart primary 0.00TB 3.00TB

To print the current partitions, enter:

(parted) print