How to Check the Size of All Databases on a cPanel Server April 25, 2025

If you’re managing a cPanel server and need to view the sizes of all MySQL databases, a quick MySQL query can give you the correct insights. This is particularly helpful for identifying large databases that might require optimization or cleanup.

Follow the guide:
Finding the 20 Largest Databases

1. Access Your Server:
   1.  Log in to your WHM panel.
   2. Go to WHM > Terminal, or connect via SSH using your preferred client.
      
   3. Run the MySQL Query:
      Execute the following command:

      mysql -e “SELECT table_schema AS ‘Database’,
      ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) AS ‘Size (MB)’
      FROM information_schema.tables
      GROUP BY table_schema
      ORDER BY SUM(data_length + index_length) DESC
      LIMIT 20;”

2. Understanding the Output
   The query will return a list of the top 20 databases, sorted by size in megabytes (MB). The output will look something like this:

   Database Size (MB)
   big_database_1   50
   big_database_2   950.75
   user_site_db     820.20

3. To List All Databases (Not Just Top 20)
   Simply remove the LIMIT 20; clause to list every database:

   mysql -e “SELECT table_schema AS ‘Database’,
   ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) AS ‘Size (MB)’
   FROM information_schema.tables
   GROUP BY table_schema
   ORDER BY SUM(data_length + index_length) DESC;”

   Alternative Method: Check Disk Usage
   For a quick, file-based check, use the du command:

   du -sh /var/lib/mysql/* | sort -hr | head -20

   Note: This method may be inaccurate for InnoDB databases since they store data in shared tablespaces.

You can use this method to view the size of all databases on a cPanel server. If you need further assistance, our support team is here to help.

Ready to set up a new database? Learn How to create a MySQL database in cPanel