I installed ubuntu 15.04 and used entire space(640 GiB) for ext4 partition but now it is showing that used space = 30.91 GiB, free space = 24.96 GiB and 536.40 GiB unallocated space. I tried to extend the space of file system using Gparted but its not working. So could any one please tell me how can I extend or allocate the space.
output after command
sudo parted -l

Gparted is not showing option for resize thats the problem.