What is the difference between MySQL Replication and DRBD?
MySQL Replication replicates data asynchronously while DRBD replicates data synchronously. Also, MySQL Replication replicates MySQL statements, while DRBD replicates the underlying block device that stores the MySQL data files. For a comparison of various high availability features between these two options, please refer to the high availability comparison grid, Chapter 14, High Availability and Scalability.