Known limitations


  • If the source is RDS MySQL, or a source that doesn't grant SUPERUSER privileges, then additional steps are required for successful migration, including a brief write downtime on the source. For more information, see the RDS-specific section for guidelines.

  • The MySQL system database isn't migrated as part of the server migration, which means information about user roles isn't included.

  • Encrypted databases can't be migrated.

  • During migration, the destination Cloud SQL database is in read-only mode, to prevent modification of the database which might break the migration process or data integrity. After the destination is promoted, it becomes writable.

  • Presently, Database Migration Service isn't compatible with MariaDB.


  • Up to 2,000 connection profiles and 1,000 migration jobs can exist at any given time. To create space for more, migration jobs (including completed ones) and connection profiles can be deleted.