This is the full step-by-step procedure to resync a master-slave replication from scratch:
At the master:
RESET MASTER; FLUSH TABLES WITH READ LOCK; SHOW MASTER STATUS;
And copy the values of the result of the last command somewhere.
Without closing the connection to the client (because it would release the read lock) issue the command to get a dump of the master:
mysqldump -u root -p --all-databases > /a/path/mysqldump.sql
Now you can release the lock, even if the dump hasn't ended yet. To do it, perform the following command in the MySQL client:
Now copy the dump file to the slave using scp or your preferred tool.
At the slave:
Open a connection to mysql and type:
Load master's data dump with this console command:
mysql -uroot -p < mysqldump.sql
Sync slave and master logs:
RESET SLAVE; CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=98;
Where the values of the above fields are the ones you copied before.
To check that everything is working again, after typing:
SHOW SLAVE STATUS;
you should see:
Slave_IO_Running: Yes Slave_SQL_Running: Yes