环境
系统 Centos7.3
MySQL版本 5.7.24
至于为什么选这个版本，emm。。。公司资源池要求的我也没办法=。=
配置
一、查看默认位置
查看 MySQL 配置文件 /etc/my.cnf
[deployer@lqas home]$ cat /etc/my.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
# datadir=/var/lib/mysql
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
[deployer@lqas home]$
可以看到默认存储在 /var/lib/mysql
二、创建新的文件夹，作为新的 MySQL 数据存储位置
sudo mkdir /home/deployer/mysql_data
sudo mkdir /home/deployer/mysql_data/mysql
三、修改所属用户为 mysql
sudo chown -R mysql:mysql /home/deployer/mysql_data/mysql
这里留个伏笔
四、修改配置文件 datadir
先停止 MySQL 服务 systemctl stop mysqld ，
然后修改配置文件：
[deployer@lqas home]$ sudo vi /etc/my.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
# datadir=/var/lib/mysql
datadir=/home/deployer/mysql_data/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
[deployer@lqas home]$
注意只修改 datadir 即可，
然后输入 :wq! 保存退出。
五、重启 MySQL 服务
[deployer@lqas home]$ systemctl restart mysqld
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
发现报错，
- 然后查看
systemctl status mysqld.service，并没有什么提示； - 再查看
journalctl -xe，提示Failed password for imonitor from 1XX.1XX.1XX.XXX port 50586 ssh2；
看起来好像是密码不对或者权限问题 - 再查看日志文件
cat /var/log/mysqld.log，没有发现 error；
然后看了网上很多解决办法，包括创建文件、搞什么软连接等等，但是对于我这个环境没有作用，查了一天，看到了这个文章 https://blog.csdn.net/u012328159/article/details/80115096，给了我提示。
六、解决报错
前面第三步我只修改了 /home/deployer/mysql_data/mysql 的所属用户，根据文章把上级目录 /home/deployer/mysql_data 的权限也修改了：
sudo chown -R mysql:mysql /home/deployer/mysql_data
然后再重启 MySQL 服务发现成功了
七、验证位置是否修改成功
进入 MySQL，查看存储位置（刚安装好需要提前配置 MySQL 密码，可以点击MySQL 设置密码查看）：
mysql> select @@datadir;
+----------------------------------+
| @@datadir |
+----------------------------------+
| /home/deployer/mysql_data/mysql/ |
+----------------------------------+
1 row in set (0.00 sec)
可以看到已经修改成功了！
撒花~~~