Note: The total storage used by an individual database and table can't be calculated if the database includes tables with variable-length columns that are longer than 768 bytes (for example, BLOB, TEXT, VARCHAR, or VARBINARY).

Reduce binary log storage

Adding a Read Replica causes the master instance's binary log to use additional storage. To find out how much storage the binary log on the master instance is using, check the

Reduce or disable general log and slow query log storage

Note: To avoid potential performance and disk use issues, disable the general and slow query logs when you're not actively using them to troubleshoot.

Manage or reduce InnoDB system tablespace size

The system tablespace contains the InnoDB data dictionary and undo space, and it starts out at 10 MB. After space is allocated, the file will always be at least that size, though long-running transactions can consume more available storage.

By default, RDS sets innodb_file_per_table to 1, which means that data for each tablespace is stored in its own .ibd file. To recover space that is marked as reusable for related tables, use the OPTIMIZE TABLE ommand to resize per table tablespace files, or drop a table.

If innodb_file_per_table is set to 0, all tables are also allocated to the system tablespace. Dropping tables or indexes, or deleting or truncating data from tables allocated in the system tablespace, marks the space previously occupied as reusable, but that command does not free up any space to the file system.

Because it's not possible to shrink the system tablespace in-place, export your current database's data and then import the data into a new instance. To reduce downtime, configure your new MySQL instance as a subordinate of the source RDS master instance. When the subordinate is synchronized with the source RDS master instance, switch to the new instance. For information about manual replication, see Replication with a MySQL or MariaDB Instance Running External to Amazon RDS.

Note: Restoring from a snapshot or creating a Read Replica won't help you recover space from the system tablespace, because both methods use a snapshot of the source instance storage volume that contains the system tablespace.