First connect to your CentOS VPS using an SSH client like Putty.
To find out how much storage is used and is available enter command: df -h
This will display the total amount of storage your VPS has, how much is used, and how much is available.
To find out how many inodes are used and available enter command: df -i
This will display the total number of inodes your VPS has, how many are used, and how many are available.