for the scenario of a daily backup on a MariaDB with InnoDB engine running on a EC2 with EBS - would a EBS snapshot be enough to have consistent backups that MariaDB could restore from?
I know that I might lose in-flight transactions without any "flushing", but for a daily backup, I accept the backup being a few (milli) seconds bit behind, as long as I have a consistent persistent state.
To my understanding Amazon EBS snapshots are consistent point-in-time snapshots (e.g via copy-on-write) of the volume, and MariaDB with a transactional storage engine guarantees transactional consistent writes to disk under all conditions.