Linux下修改MySQL数据库数据文件路径

使用rpm安装方式安装完MySQL数据库后，数据文件的默认路径为/var/lib/mysql，然而根目录并不适合用于存储数据文件。

原路径：/var/lib/mysql
目标路径：/home/mysql_data/mysql
Linux系统版本：centos7.6
MySQL数据库版本：5.7.25

步骤：
1、创建目标路径
mkdir -p /home/mysql_data
2、关闭MySQL
systemctl stop mysqld
3、复制数据文件
cp -arp /var/lib/mysql /home/mysql_data
4、修改配置文件/etc/my.cnf
将datadir和socket中的原路径修改为目标路径
datadir=/home/mysql_data/mysql
socket=/home/mysql_data/mysql/mysql.sock
5、启动MySQL服务
systemctl start mysqld

NOTE:
1、报错如下：

2019-12-22T08:32:42.430564Z 0 [ERROR] InnoDB: Operating system error number 13 in a file operation.
2019-12-22T08:32:42.430599Z 0 [ERROR] InnoDB: The error means mysqld does not have the access rights to the directory.
2019-12-22T08:32:42.430616Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2019-12-22T08:32:42.430898Z 0 [ERROR] InnoDB: The innodb_temporary data file 'ibtmp1' must be writable
2019-12-22T08:32:42.430923Z 0 [ERROR] InnoDB: The innodb_temporary data file 'ibtmp1' must be writable
2019-12-22T08:32:42.430936Z 0 [ERROR] InnoDB: Could not create the shared innodb_temporary.
2019-12-22T08:32:42.430952Z 0 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2019-12-22T08:32:43.038973Z 0 [ERROR] InnoDB: Operating system error number 13 in a file operation.
2019-12-22T08:32:43.039021Z 0 [ERROR] InnoDB: The error means mysqld does not have the access rights to the directory.
2019-12-22T08:32:43.039037Z 0 [ERROR] Plugin 'InnoDB' init function returned error.
2019-12-22T08:32:43.039046Z 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2019-12-22T08:32:43.039056Z 0 [ERROR] Failed to initialize builtin plugins.
2019-12-22T08:32:43.039063Z 0 [ERROR] Aborting

解决：
执行命令：
setenforce 1
再重新启动

2、报错如下：
Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock'
解决：
修改配置文件my.cnf,添加或修改如下配置：

[client]
socket = /home/mysql_data/mysql/mysql.sock