Grow ext4 or xfs partitions to its maximum size

For EXT4 partitions:

resize2fs /dev/xvda1

For XFS:

xfs_growfs -d /dev/xvda1

Replace xvda1 with the partition of your choice! I ran into this problem using AWS instances in which I had to increase the size of the root partitions of an EBS volume.

Type df -h to show your currently mounted partitions and disk usage.