Extra instance of MariaDB or mysql in Debian Linux doesn't work when I change a name during the setup

**-- EDIT -- Complete setup in the answer below. -- EDIT --** When I follow an article (link below) on how to setup a extra MariaDB or Mysql on Linux, and it works. However, I don't like the name "mysql1" & "mysql2" for instance names. But when I change just that aspect of the code, the server wont install when I run the start command. I wrote both setups here below for easy comparison: The one that does work where 2 instances are being made, and the one that ultimately doesn't work. I would very much love to figure how to make the one that doesn't work, work. Your help is very much appreciated! **- 1) Datadir (setup that works):** sudo mkdir -p -v /var/lib/mysql{1..2} sudo chown mysql:mysql -v /var/lib/mysql{1..2} **- 1) Datadir (setup that ultimately doesn't work):** sudo mkdir -p -v /var/lib/mysqlTest sudo chown mysql:mysql -v /var/lib/mysqlTest **- 2) Socket directory (setup that works):** sudo mkdir -p -v /usr/local/mysql/mdb{1..2} sudo chown -v -R mysql:mysql /usr/local/mysql/mdb{1..2} **- 2) Socket directory(setup that ultimately doesn't work):** sudo mkdir -p -v /usr/local/mysql/mdbTest sudo chown -v -R mysql:mysql /usr/local/mysql/mdbTest **- 3) Log directory (setup that works):** sudo mkdir -p -v /var/log/mysql{1..2} sudo chown -v -R mysql:mysql /var/log/mysql{1..2} **- 3) Log directory(setup that ultimately doesn't work):** sudo mkdir -p -v /var/log/mysqlTest sudo chown -v -R mysql:mysql /var/log/mysqlTest **- 4) I create the following file** "mysqld_multi_cls.cnf" Located at: /etc/mysql/ **- 5) content (setup that works):** # Configuration Settings for mysqld_multi , as well as separate instances. # [mysqld_multi] mysqld = /usr/bin/mysqld_safe mysqladmin = /usr/bin/mysqladmin [mysqld1] socket = /tmp/mysql.sock1 port = 3307 pid-file = /usr/local/mysql/mdb1/ansible-host1.pid1 datadir = /var/lib/mysql1 log-error = /var/log/mysql1/error.log log_bin = /var/lib/mysql1/mdb1-mysql-bin.log server-id = 1 expire_logs_days = 72 sync_binlog = 1 innodb_flush_log_at_trx_commit = 1 innodb_flush_method = O_DIRECT binlog_format = mixed gtid_strict_mode = 1 [mysqld2] socket = /tmp/mysql.sock2 port = 3308 pid-file = /usr/local/mysql/mdb2/ansible-host1.pid2 datadir = /var/lib/mysql2 log-error = /var/log/mysql2/error.log log-bin = /var/lib/mysql2/mdb2-mysql-bin.log server-id = 2 expire_logs_days = 64 sync_binlog = 1 innodb_flush_log_at_trx_commit = 1 innodb_flush_method = O_DIRECT binlog_format = mixed gtid_strict_mode = 1 **- 5) content(setup that ultimately doesn't work):** # Configuration Settings for mysqld_multi , as well as separate instances. # [mysqld_multi] mysqld = /usr/bin/mysqld_safe mysqladmin = /usr/bin/mysqladmin [mysqlTest] socket = /tmp/mysql.sock3 port = 3309 pid-file = /usr/local/mysql/mdbTest/ansible-host1.pid3 datadir = /var/lib/mysqlTest log-error = /var/log/mysqlTest/error.log log_bin = /var/lib/mysqlTest/mdbTest-mysql-bin.log server-id = 3 expire_logs_days = 72 sync_binlog = 1 innodb_flush_log_at_trx_commit = 1 innodb_flush_method = O_DIRECT binlog_format = mixed gtid_strict_mode = 1 **-6) And now we start the server:** sudo mysqld_multi --defaults-file=/etc/mysql/mysqld_multi_cls.cnf --log=/etc/mysql/multi_ins.log start - If done in the 1st manor, the database is now installing and everyone is happy. - But if done in the 2nd manor where I only changed the name and made a single (extra) instance, nothing happens. What am I missing? Cheers and thank you very much! Here is the article on Linkedin by Michael Amadi: https://www.linkedin.com/pulse/running-multiple-instances-mariadb-single-server-different-amadi