centos7 安裝mysql 資料庫路徑改變後selinux問題導致不能啟動mysqld
想請教是我少修改什麼地方還是設定方式有問什麼問題
環境：

3.10.0-1062.18.1.el7.x86_64 #1 SMP Tue Mar 17 23:49:17 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

CentOS Linux release 7.7.1908 (Core)

安裝方法

curl -L -O  https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm
rpm -i  mysql80-community-release-el7-3.noarch.rpm
sudo yum install mysql-community-server

mv /var/lib/mysql /db/mysql
chcon -R -t mysqld_db_t /db/mysql
ls -ZL /db | grep "my"
#check selinux
vim /etc/my.cnf
#changepath
systemctl start mysqld

錯誤後再做ls -Z發現回變回default

[root@DB01 db]# ll -Z
drwxrwx---. mysql mysql unconfined_u:object_r:default_t:s0 mysql
-rw-r--r--. root  root  unconfined_u:object_r:default_t:s0 mysql80-community-release-el7-3.noarch.rpm
[root@DB01 db]#
[root@DB01 db]# chcon -R -t mysqld_db_t /db/mysql
[root@DB01 db]# ll -Z
drwxrwx---. mysql mysql unconfined_u:object_r:mysqld_db_t:s0 mysql
-rw-r--r--. root  root  unconfined_u:object_r:default_t:s0 mysql80-community-release-el7-3.noarch.rpm
[root@DB01 db]# systemctl start mysqld
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
[root@DB01 db]# ll -Z
drwxrwx---. mysql mysql unconfined_u:object_r:default_t:s0 mysql
-rw-r--r--. root  root  unconfined_u:object_r:default_t:s0 mysql80-community-release-el7-3.noarch.rpm
[root@DB01 db]#

已測試關閉selinux後能正常啟動mysqld