We receive this question about the ibdata1 file in MySQL very often in Percona Support.
The panic starts when the monitoring server sends an alert about the storage of the MySQL server – saying that the disk is about to get filled.
After some research you realize that most of the disk space is used by the InnoDB’s shared tablespace ibdata1. You have innodb_file_per_table enabled, so the question is:
What is stored in ibdata1?
When you have innodb_file_per_table enabled, the tables are stored in their own tablespace but the shared tablespace is still used to store other InnoDB’s internal …[Read more]