【Maria DB】同一サーバ上に複数インスタンスを作成する方法

daimaru@Daimaru_Test:~$ sudo mkdir /var/lib/mysql_second
daimaru@Daimaru_Test:~$ sudo chown -R mysql:mysql /var/lib/mysql_second

[mysqld.second] ###systemctl start mariadb@<ホゲホゲ>で使う名前を入力###
port = 3307
datadir = /var/lib/mysql_second
socket = /run/mysqld/mysqld2.sock
log_error = /var/log/mysql/error2.log

daimaru@Daimaru-test:/etc/mysql/mariadb.conf.d$ sudo mariadb-install-db --user=mysql --datadir=/var/lib/mysql_second
Installing MariaDB/MySQL system tables in '/var/lib/mysql_second' ...
OK

To start mariadbd at boot time you have to copy
support-files/mariadb.service to the right place for your system


Two all-privilege accounts were created.
One is root@localhost, it has no password, but you need to
be system 'root' user to connect. Use, for example, sudo mariadb
The second is mysql@localhost, it has no password either, but
you need to be the system 'mysql' user to connect.
After connecting you can set the password, if you would need to be
able to connect as any of these users with a password and without sudo

See the MariaDB Knowledgebase at https://mariadb.com/kb

You can start the MariaDB daemon with:
cd '/usr' ; /usr/bin/mariadbd-safe --datadir='/var/lib/mysql_second'

You can test the MariaDB daemon with mariadb-test-run.pl
cd '/usr/share/mariadb/mariadb-test' ; perl mariadb-test-run.pl

Please report any problems at https://mariadb.org/jira

The latest information about MariaDB is available at https://mariadb.org/.

Consider joining MariaDB's strong and vibrant community:
https://mariadb.org/get-involved/

daimaru@Daimaru-test:$ sudo touch /var/log/mysql/error2.log
daimaru@Daimaru-test:$ sudo chown mysql:mysql /var/log/mysql/error2.log
daimaru@Daimaru-test:$ sudo chmod 660 /var/log/mysql/error2.log

daimaru@Daimaru-test:$ sudo systemctl daemon-reload
daimaru@Daimaru-test:$ sudo systemctl start mariadb@secondary

Daimaru@Daimaru-Test:/etc/mysql/mariadb.conf.d$ sudo systemctl status mariadb@second
● mariadb@second.service - MariaDB 11.4.10 database server (multi-instance second)
     Loaded: loaded (/lib/systemd/system/mariadb@.service; disabled; vendor preset: enabled)
     Active: active (running) since Mon 2026-03-16 15:54:55 JST; 10s ago
       Docs: man:mariadbd(8)
             https://mariadb.com/kb/en/library/systemd/
    Process: 857432 ExecStartPre=/usr/bin/mariadb-install-db $MYSQLD_MULTI_INSTANCE --rpm (code=exited, status=0/SUCCESS)
    Process: 857457 ExecStartPost=/etc/mysql/debian-start (code=exited, status=0/SUCCESS)
   Main PID: 857446 (mariadbd)
     Status: "Taking your SQL requests now..."
      Tasks: 11 (limit: 15227)
     Memory: 110.9M
        CPU: 525ms
     CGroup: /system.slice/system-mariadb.slice/mariadb@second.service
             └─857446 /usr/sbin/mariadbd --defaults-group-suffix=.second

sudo mariadb -P 3307 -S /run/mysqld/mysqld2.sock -u root