root@mylnx12:~# find / -name "my.cnf"/etc/alternatives/my.cnf/etc/mysql/my.cnf/var/lib/dpkg/alternatives/my.cnfroot@mylnx12:~# locate my.cnf/etc/alternatives/my.cnf/etc/mysql/my.cnf/etc/mysql/my.cnf.fallback/var/lib/dpkg/alternatives/my.cnfroot@mylnx12:~# mysql --help | grep my.cnf      order of preference, my.cnf, $MYSQL_TCP_PORT,/etc/my.cnf /etc/mysql/my.cnf ~/.my.cnf root@mylnx12:~# mysqld --verbose --help | grep -A 1 'Default options'Default options are read from the following files in the given order:/etc/my.cnf /etc/mysql/my.cnf ~/.my.cnf 

root@mylnx12:~# ls -lrt /etc/alternatives/my.cnflrwxrwxrwx 1 root root 20 Sep 28 16:28 /etc/alternatives/my.cnf -> /etc/mysql/mysql.cnf

root@mylnx12:~# cat /var/lib/dpkg/alternatives/my.cnfauto/etc/mysql/my.cnf /etc/mysql/my.cnf.fallback100/etc/mysql/mysql.cnf200

root@mylnx12:~# cat /etc/mysql/my.cnf## The MySQL database server configuration file.## You can copy this to one of:# - "/etc/mysql/my.cnf" to set global options,# - "~/.my.cnf" to set user-specific options.# # One can use all long options that the program supports.# Run program with --help to get a list of available options and with# --print-defaults to see which it would actually understand and use.## For explanations see# http://dev.mysql.com/doc/mysql/en/server-system-variables.html ## * IMPORTANT: Additional settings that can override those from this file!#  The files must end with '.cnf', otherwise they'll be ignored.# !includedir /etc/mysql/conf.d/!includedir /etc/mysql/mysql.conf.d/

root@mylnx12:~# cd /etc/mysql/mysql.conf.d/root@mylnx12:/etc/mysql/mysql.conf.d# ls -lrttotal 8-rw-r--r-- 1 root root  21 Feb 4 2017 mysqld_safe_syslog.cnf-rw-r--r-- 1 root root 3148 Oct 6 23:34 mysqld.cnfroot@mylnx12:/etc/mysql/mysql.conf.d# cat mysqld.cnf## The MySQL database server configuration file.## You can copy this to one of:# - "/etc/mysql/my.cnf" to set global options,# - "~/.my.cnf" to set user-specific options.# # One can use all long options that the program supports.# Run program with --help to get a list of available options and with# --print-defaults to see which it would actually understand and use.## For explanations see# http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients# It has been reported that passwords should be enclosed with ticks/quotes# escpecially if they contain "#" chars...# Remember to edit /etc/mysql/debian.cnf when changing the socket location. # Here is entries for some specific programs# The following values assume you have at least 32M ram [mysqld_safe]socket     = /var/run/mysqld/mysqld.socknice      = 0 [mysqld]## * Basic Settings#user      = mysqlpid-file    = /var/run/mysqld/mysqld.pidsocket     = /var/run/mysqld/mysqld.sockport      = 3306basedir     = /usrdatadir     = /var/lib/mysqltmpdir     = /tmplc-messages-dir = /usr/share/mysqlskip-external-lockinglog_bin    = mylnx12_binserver_id   = 0character-set-server=utf8mb4collation-server=utf8mb4_general_ci ## Instead of skip-networking the default is now to listen only on# localhost which is more compatible and is not less secure.bind-address      = 10.21.6.7## * Fine Tuning#key_buffer_size     = 16Mmax_allowed_packet   = 100Mthread_stack      = 192Kthread_cache_size    = 8# This replaces the startup script and checks MyISAM tables if needed# the first time they are touchedmyisam-recover-options = BACKUP#max_connections    = 100#table_cache      = 64#thread_concurrency   = 10## * Query Cache Configuration#query_cache_limit    = 1Mquery_cache_size    = 16M## * Logging and Replication## Both location gets rotated by the cronjob.# Be aware that this log type is a performance killer.# As of 5.1 you can enable the log at runtime!#general_log_file    = /var/log/mysql/mysql.log#general_log       = 1## Error log - should be very few entries.#log_error = /var/log/mysql/error.log## Here you can see queries with especially long duration#log_slow_queries    = /var/log/mysql/mysql-slow.log#long_query_time = 2#log-queries-not-using-indexes## The following can be used as easy to replay backup logs or for replication.# note: if you are setting up a replication slave, see README.Debian about#    other settings you may need to change.#server-id       = 1#log_bin            = /var/log/mysql/mysql-bin.logexpire_logs_days    = 10max_binlog_size  = 100M#binlog_do_db      = include_database_name#binlog_ignore_db    = include_database_name## * InnoDB## InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.# Read the manual for more InnoDB related options. There are many!## * Security Features## Read the manual, too, if you want chroot!# chroot = /var/lib/mysql/## For generating SSL certificates I recommend the OpenSSL GUI "tinyca".## ssl-ca=/etc/mysql/cacert.pem# ssl-cert=/etc/mysql/server-cert.pem#: ssl-key=/etc/mysql/server-key.pem