The MariaDB Server has to be accessible from outside. For Debian, one has to comment `bind-address=127.0.0.1` in the file `/etc/mysql/mariadb.conf.d/50-server.cnf`.
If you have any firewall enabled, make sure to allow port 3306/TCP.
Add this segment at the end of `/etc/mysql/my.cnf`
```
[mariadb]
log-bin
server_id=1
log-basename=master
binlog-format=mixed
```
**Restart mariadb** now
Create a replication user
```
CREATE USER 'replication'@'%' IDENTIFIED BY '<password>';
GRANT REPLICATION SLAVE ON *.* TO 'replication'@'%';
```
Next we have to get the data necessary so the slave knows where to start replicating.
`FLUSH TABLES WITH READ LOCK;`
`SHOW MASTER STATUS;`
**Do not close this session, keep it running until you have made the backup from the next step**
`# mysqldump -u root -p (db name) > db_name.sql`
You can unlock the database again.
`UNLOCK TABLES;`
### Slave Configuration
Edit your `/etc/mysql/my.cnf` file
Make sure to choose different IDs for every host
```
[mysqld]
server-id = 2
```
Create the database and restore the sql dumps made earlier.
`# mysql -u root -p (db name) < db_name.sql`
Set the database master now
```
CHANGE MASTER TO
MASTER_HOST='<domain>',
MASTER_USER='replication',
MASTER_PASSWORD='<password>',
MASTER_PORT=3306,
MASTER_LOG_FILE='<masterlogfile>',
MASTER_LOG_POS=<masterlogposition>,
MASTER_CONNECT_RETRY=10,
MASTER_USE_GTID = slave_pos;
```
Start slave now
`START SLAVE;`
And check the status
`SHOW SLAVE STATUS \G`
If both of the following options say yes, everything is working as intended
