It's very wried to see my actual disk size is much less than the actual size. From the information, looks this disk is not be partitioned.
I have no idea why the actual size is 20G but disk size is 100G, and how could I find other 80G back?
The image version is stardard AWS Linux AMI:
NAME="Amazon Linux AMI"
VERSION="2014.09"
ID="amzn"
ID_LIKE="rhel fedora"
VERSION_ID="2014.09"
PRETTY_NAME="Amazon Linux AMI 2014.09"
ANSI_COLOR="0;33"
CPE_NAME="cpe:/o:amazon:linux:2014.09:ga"
HOME_URL="http://aws.amazon.com/amazon-linux-ami/"
Amazon Linux AMI release 2014.09
Best Answer
Did you expand the storage at any point? It looks like the file system wasn't resized when the underlying storage was increased.
For ext3/ext4 you would use resize2fs to grow the file system. For XFS you would use grow_xfs. More information.