I connected a new internal HDD to my headless ubuntu server and would like to partition it so I can copy my existing system disk to it (the existing disk is way low on free space and the new disk is larger.)

The disk shows in /dev/sdd (there is not sdd1 or any partitions showing). Yet the new disk does not show up using fdisk -l and attempts to mount keep referring to fstab.

Code:
tom@HouseMedia:/$ mount /dev/sdd
mount: can't find /dev/sdd in /etc/fstab or /etc/mtab
tom@HouseMedia:/$ mount /dev/sdd1
mount: can't find /dev/sdd1 in /etc/fstab or /etc/mtab
I had previously mounted and partition this drive but after using dd to restore a disk image of my existing system disk, the new disk was still empty. I'm a little lost on what exactly is wrong and would appreciate some help on getting back to square one again!