没有内部MySQL命令来跟踪这个，它有点过于抽象。该文件可能位于5个（或更多？）位置，并且它们都有效，因为它们加载了级联。
- /etc/my.cnf中
- /etc/mysql/my.cnf
- $ MYSQL_HOME/my.cnf中
- [DATADIR] /my.cnf
- 〜/ .my.cnf
这些是MySQL看到的默认位置。如果它找到多个，它将加载它们中的每一个和值互相覆盖（按照列出的顺序，我认为）。此外，--defaults-file参数可以覆盖整个事物，所以...基本上，它是一个巨大的痛苦的屁股。
但是由于它如此混乱，很有可能它只是在/etc/my.cnf中。
（如果您只想查看值： SHOW VARIABLES ，但您需要权限才能这样做。）
您实际上可以“请求”MySQL以查找其搜索my.cnf（或Windows上的my.ini）的所有位置的列表。但它不是SQL查询。相反，执行：
$ mysqladmin --help
或者，在5.7之前：
$ mysqld --help --verbose
在第一行中，您将找到一条消息，其中包含所查找的所有my.cnf位置的列表。在我的机器上它是：
Default options are read from the following files in the given order:
/etc/my.cnf
/etc/mysql/my.cnf
/usr/etc/my.cnf
~/.my.cnf
或者，在Windows上：
Default options are read from the following files in the given order:
C:\Windows\my.ini
C:\Windows\my.cnf
C:\my.ini
C:\my.cnf
C:\Program Files\MySQL\MySQL Server 5.5\my.ini
C:\Program Files\MySQL\MySQL Server 5.5\my.cnf
但请注意， 可能是这些位置中没有my.cnf文件的情况 。因此，您可以自己创建文件 - 使用MySQL发行版提供的示例配置文件之一（在Linux上 - 请参阅/usr/share/mysql/*.cnf文件并使用适合您的文件 - 将其复制到/etc/my.cnf然后根据需要进行修改）。
另外，请注意 还有一个命令行选项--defaults-file，它可以定义my.cnf或my.ini文件的自定义路径。例如，Windows上的MySQL 5.5就是这种情况 - 它指向数据目录中的my.ini文件，该文件通常不会与mysqld --help --verbose一起列出。在Windows上 - 请参阅服务属性以查明是否适合您。
最后，检查 https://dev.mysql.com/doc/refman/8.0/en/option-files.html - 更详细地描述了它。
你总是可以在终端上运行find。
find / -name my.cnf
您可以使用 ：
locate my.cnf
whereis my.cnf
find . -name my.cnf
这可能有效：
strace mysql ";" 2>&1 | grep cnf
在我的机器上输出：
stat64("/etc/my.cnf", 0xbf9faafc) = -1 ENOENT (No such file or directory)
stat64("/etc/mysql/my.cnf", {st_mode=S_IFREG|0644, st_size=4271, ...}) = 0
open("/etc/mysql/my.cnf", O_RDONLY|O_LARGEFILE) = 3
read(3, "# /etc/mysql/my.cnf: The global "..., 4096) = 4096
stat64("/home/xxxxx/.my.cnf", 0xbf9faafc) = -1 ENOENT (No such file or directory)
所以看起来/etc/mysql/my.cnf是一个，因为它的stat64（）和read（）是成功的。
默认情况下，mysql首先在/ etc文件夹中搜索my.cnf。如果此文件夹中没有/etc/my.cnf文件，我建议您在文件夹中创建一个新文件（ https://dev.mysql.com/doc/refman/5.6/en /option-files.html ）。
您还可以搜索由mysql安装提供的现有my.cnf。您可以启动以下命令
Sudo find / -name "*.cnf"
您可以将以下配置文件与myisam表一起使用，并且不支持innodb mysql（来自mac os x maverick上的mysql端口安装）。请验证此配置文件中的每个命令。
# Example MySQL config file for large systems.
#
# This is for a large system with memory = 512M where the system runs mainly
# MySQL.
#
# MySQL programs look for option files in a set of
# locations which depend on the deployment platform.
# You can copy this option file to one of those
# locations. For information about these locations, see:
# http://dev.mysql.com/doc/mysql/en/option-files.html
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.
# The following options will be passed to all MySQL clients
[client]
#password = your_password
port = 3306
socket = /opt/local/var/run/mysql5/mysqld.sock
# Here follows entries for some specific programs
# The MySQL server
[mysqld]
port = 3306
socket = /opt/local/var/run/mysql5/mysqld.sock
skip-locking
key_buffer_size = 256M
max_allowed_packet = 1M
table_open_cache = 256
sort_buffer_size = 1M
read_buffer_size = 1M
read_rnd_buffer_size = 4M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_size= 16M
# Try number of CPU's*2 for thread_concurrency
thread_concurrency = 8
# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same Host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
#
#skip-networking
# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin
# binary logging format - mixed recommended
binlog_format=mixed
# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-Host is not set
# but will not function as a master if omitted
server-id = 1
# Replication Slave (comment out master section to use this)
#
# To configure this Host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
# the syntax is:
#
# CHANGE MASTER TO MASTER_Host=<Host>, MASTER_PORT=<port>,
# MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
# where you replace <Host>, <user>, <password> by quoted strings and
# <port> by the master's port number (3306 by default).
#
# Example:
#
# CHANGE MASTER TO MASTER_Host='125.564.12.1', MASTER_PORT=3306,
# MASTER_USER='joe', MASTER_PASSWORD='secret';
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
# start replication for the first time (even unsuccessfully, for example
# if you mistyped the password in master-password and the slave fails to
# connect), the slave will create a master.info file, and any later
# change in this file to the variables' values below will be ignored and
# overridden by the content of the master.info file, unless you shutdown
# the slave server, delete master.info and restart the slaver server.
# For that reason, you may want to leave the lines below untouched
# (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-Host is set
# but will not function as a slave if omitted
#server-id = 2
#
# The replication master for this slave - required
#master-Host = <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user = <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password = <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port = <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin
# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = /opt/local/var/db/mysql5
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = /opt/local/var/db/mysql5
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 256M
#innodb_additional_mem_pool_size = 20M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 64M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates
[myisamchk]
key_buffer_size = 128M
sort_buffer_size = 128M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
正如konyak所述，您可以通过运行my.cnf获取mysql将查找mysqladmin --help文件的位置列表。由于这非常详细，您可以快速找到您关心的部分：
$ mysqladmin --help | grep -A1 'Default options'
这将为您提供类似于以下的输出：
Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/local/etc/my.cnf ~/.my.cnf
根据您安装mysql的方式，可能还没有这些文件存在。你可以cat它们，以便了解你的配置是如何构建的，如果你需要在你喜欢的位置创建自己的my.cnf。
对于Ubuntu 16：/etc/mysql/mysql.conf.d/mysqld.cnf
尝试运行mysqld --help --verbose | grep my.cnf | tr " " "\n"
输出将是类似的
/etc/my.cnf
/etc/mysql/my.cnf
/usr/local/etc/my.cnf
~/.my.cnf
我不知道你是如何在你的Linux环境中设置MySQL但是你检查了吗？
- /etc/my.cnf中
如果您使用的是Homebrew的Mac，请使用
brew info mysql
你会看到类似的东西
$ brew info mysql
mysql: stable 5.6.13 (bottled)
http://dev.mysql.com/doc/refman/5.6/en/
Conflicts with: mariadb, mysql-cluster, percona-server
/usr/local/Cellar/mysql/5.6.13 (9381 files, 354M) *
最后一行是INSTALLERDIR每个MySQL文档
发现我的使用
mysqld --help --verbose | grep my.cnf
另一种选择是使用whereis命令。
例如。哪里是my.cnf
所有伟大的建议，在我的情况下我没有在任何这些位置找到它，但在/usr/share/mysql中，我有一个RHEL VM并且我安装了mysql5.5
您必须根据您的MySQL版本查看各个位置。
mysqld --help -verbose | grep my.cnf
For Homebrew:
/usr/local/Cellar/mysql/8.0.11/bin/mysqld (mysqld 8.0.11)
Default possible locations:
/etc/my.cnf
/etc/mysql/my.cnf
~/.my.cnf
Found mine here:
/usr/local/etc/my.cnf
仅回答MySQL Workbench用户，
如果您使用的是MAMP，请访问模板> MySQL（my.cnf）> [版本]
如果您正在运行无窗口MAMP，则可能需要使用“自定义”按钮自定义工具栏。
在Ubuntu上（直接编辑）：
$ Sudo nano /etc/mysql.conf.d/mysqld.cnf
对我来说，我有“ENGINE = MyISAM”类表，一旦我将其更改为“ENGINE = InnoDB”，它在ASP.NET应用服务上的PhpMyAdmin中工作:)
我在 ubuntu 中安装了带Apache, php and mysql的xampp软件包。 my.cnf文件位于/opt/lampp/etc/文件夹中。希望它能帮助别人。