One way to create a snapshot of the data in an existing master database is to use the mysqldump tool. Once the data dump has been completed, you then import this data into the slave before starting the replication process.
To obtain a snapshot of the data using mysqldump:
If you have not already locked the tables on the server to prevent statements that update data from executing:
Start a session on the server by connecting to it with the
command-line client, and flush all tables and block write
statements by executing the
FLUSH TABLES WITH
READ LOCK statement:
FLUSH TABLES WITH READ LOCK;
Remember to use
STATUS and record the binary log details for use
when starting up the slave. The point in time of your
snapshot and the binary log position must match. See
Section 220.127.116.11, “Obtaining the Replication Master Binary Log Coordinates”.
In another session, use mysqldump to create a dump either of all the databases you want to replicate, or of selected individual databases. For example:
mysqldump --all-databases --lock-all-tables >dbdump.db
An alternative to using a bare dump, is to use the
--master-data option, which automatically
CHANGE MASTER TO
statement required on the slave to start the replication
mysqldump --all-databases --master-data >dbdump.db
In the client where you acquired the read lock, release the lock:
Alternatively, exit the first session to release the read lock.
When choosing databases to include in the dump, remember to filter out databases on each slave that you do not want to include in the replication process.
Either to copy the dump file to the slave, or use the file from the master when connecting remotely to the slave to import the data.