Configuring MariaDB for DRBD

Once you have configured DRBD and have an active DRBD device and file system, you can configure MariaDB to use the chosen device to store the MariaDB data.

When performing a new installation of MySQL, you can either select to install MariaDB entirely onto the DRBD device, or just configure the data directory to be located on the new file system.

In either case, the files and installation must take place on the primary node, because that is the only DRBD node on which you can mount the DRBD device file system as read/write.

Store the following files and information on your DRBD device:

• MySQL data files, including the binary log, and InnoDB data files.
• MySQL configuration file (my.cnf).

To set up MariaDB to use your new DRBD device and file system:

1. If you are migrating an existing MariaDB installation, stop MySQL:

   shell> mysqladmin shutdown
   

2. Copy the my.cnf onto the DRBD device. If you are not already using a configuration file, copy one of the sample configuration files from the MariaDB distribution.

   root-shell> mkdir /mnt/drbd/mysql root-shell> cp /etc/my.cnf /mnt/drbd/mysql
   

3. Copy your MariaDB data directory to the DRBD device and mounted file system.

   root-shell> cp -R /var/lib/mysql /drbd/mysql/data
   

4. Edit the configuration file to reflect the change of directory by setting the value of the datadir option. If you have not already enabled the binary log, also set the value of the log-bin option.

   datadir = /drbd/mysql/data
    log-bin = mysql-bin
   

5. Create a symbolic link from /etc/my.cnf to the new configuration file on the DRBD device file system.

   root-shell> ln -s /drbd/mysql/my.cnf /etc/my.cnf
   

6. Now start MariaDB and check that the data that you copied to the DRBD device file system is present.

   root-shell> /etc/init.d/mysql start
   

Your MariaDB data should now be located on the file system running on your DRBD device. The data is physically stored on the underlying device that you configured for the DRBD device. Meanwhile, the content of your MariaDB databases is copied to the secondary DRBD node.

Note that you cannot access the information on your secondary node, as a DRBD device working in secondary mode is not available for use.

Retornar