For all newbies, it is a common problem when we quickly run out of space (especially if you are a web developer)

Therefore, this tutorial is for users who have much space in home directory but still runs of out space in root

Help from
https://ask.fedoraproject.org/en/question/55867/how-can-i-move-space-from-one-partition-to-another/

Make sure all your hd is ext4 formatted and you are logged in as Root

Now install the software

yum install lvm2

Firstly check the directory structure of CentOS

lvs

To reduce space from home directory type following:

lvreduce --resizefs --size -700G /dev/centos/home 

To Extend space in root directory type following:

lvextend --resizefs --size +700G /dev/centos/root