View and modify the MySQL data storage directory under centos7

Software version

1. CentOS 7
2. MySQL 5.7

View the data storage directory

Use command

SHOW VARIABLES LIKE '%datadir%';

#  perhaps 
SELECT @@datadir;

Get the default storage directory ：/var/lib/mysql

mobile data

stop it mysql service

systemctl stop mysqld

Create a new data storage directory

mkdir -p /data01/mysql/data

Copy the data

take mysql Copy directory to /data01/mysql/data Under the table of contents

cp  -a /var/lib/mysql /data01/mysql/data/ 

Add permissions to the directory

chown -R mysql:mysql /data01/mysql/data/mysql 
chown -R mysql:mysql /data01/mysql/data

Modify the configuration my.cnf

open /etc/my.cnf file , find [mysqld] keyword , modify datadir and socket Value

[mysqld]
datadir=/data01/mysql/data/mysql
socket=/data01/mysql/data/mysql/mysql.sock

restart mysql service

systemctl start mysqld

problem

Error phenomenon

After restart , The project can normally access the database , But using the command line to access the database will report an error :

mysql -uroot -p
......
Can't connect to local MySQL server through socket '/var/lib/mysql'
......

solve

modify /etc/my.cnf, find [client] paragraph , Add the configuration

[client]
default-character-set=utf8mb4
port=3306
socket=/data01/mysql/data/mysql/mysql.sock

socket Field may not exist , Can be added to .