I cloned my hard-drive and extended the root partition using GParted (with live-cd). But when I boot into ubuntu, the extra size does not show up.
After searching around, I am lost as nothing has worked. Any suggestion/opinion at this point is greatly appreciated. Thanks.
It is possible that the file system was not grown to fill the partition. If this is the case then run gparted (best done from live media so no partitions are mounted), select the partition and choose Partition -> Check, then Edit -> Apply. This should grow the file system to fill the partition.
However, if the partition uses Logical Volume Managment (lvm2 pv), then you will need to use commands like lvresize to grow the Logical Volume within the Physical Volume.