What you seem to have done is create a partition on your new disk that is the same size as your old disk. The rest of your new disk is empty, and unpartitioned and unformatted: so it is currently unusable.
You can:
Either use fdisk to create a linux partition on the free space of your new disk, and then create a filesystem there and then mount it (perhaps as /home?).
Or go back to running linux from your old disk, use fdisk to repartition your new disk, make a filesystem on your new disk's partition(s), and then copy all your files to the new disk and make it bootable. There are plenty of posts on this board about moving linux installations to a new, usually bigger HDD.
Good luck!
EDIT : Here's a link about how to do the second option:
http://www.linuxquestions.org/questi...01#post1243901