be very careful when throwing around terms like 'backup' and 'primary'. these are not servers. they are roles. they switch. when controller.sh is renamed, it is because of a hard (persistent) failure. you had a failover where the primary was not accessible at the time of the failover. the logic here is that you cannot trust the state of the database on the former primary, so we disable the database from starting and potentially corrupting the system state. on failover, if you can't set the primary database passive, then you disable it to prevent the possibility of a split brain. recovery without re-replicate requires all of the following: make sure skip-slave-start=true is in both db.cnf, this prevents any replication from running while doing the checks. then, make sure that replication is stopped by running 'stop slave' on the primary. then, start the secondary database by renaming controller.sh-disabled to controller.sh and chmod +x the file. check the db health. update global_configuration_local to passive and secondary <- do NOT forget this step. then start the slave on the secondary. after running for a while, seconds behind master will be zero, and you can remove skip-slave-start from db.cnf on both machines and you can start the slave on the primary. if you don't understand every word of the foregoing, you can easily trash your installation. open a ticket if you need help. ... View more