You may see the mysql database size is zero in cPanel >> Mysql Databases, though the databases contains tables and data. In order to include the size of the databases while displaying disk usage in cPanel/WHM, use either of the following steps:
1) SSH to your server as root and edit the cpanel.config file
# vi /var/cpanel/cpanel.config
Search for
disk_usage_include_sqldbs=0
and change to
disk_usage_include_sqldbs=1
If the parameter is not present, add it. Save the file and execute the following command:
# /scripts/update_db_cache
OR You may use follwing option in WHM
2) Login to the WHM, goto Tweak Settings >> ‘SQL’ section and enable the following option:
When displaying disk usage in cpanel/WHM include Postgresql and MySQL.