修改mysql端口后重启mysql报错：Can't start server: Bind on TCP/IP port. Got error...n denied

1：错误信息:如下

[root@host ~]# systemctl status mariadb
● mariadb.service - MariaDB 10.2. database server
   Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/mariadb.service.d
           └─migrated-from-my.cnf-settings.conf
   Active: failed (Result: exit-code) since Fri -- :: CST; 1min 16s ago
     Docs: man:mysqld()
           https://mariadb.com/kb/en/library/systemd/
  Process:  ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS --basedir=/usr $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=exited, status=/FAILURE)
  Process:  ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`/usr/bin/galera_recovery`; [ $? -eq  ]   && systemctl set-environment _WSREP_START_POSITION=$VAR || exit  (code=exited, status=/SUCCESS)
  Process:  ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=/SUCCESS)
 Main PID:  (code=exited, status=/FAILURE)
   Status: "MariaDB server is down"

Dec  :: host---- mysqld[]: --  ::  [Note] InnoDB: Buffer pool(s) load completed at   ::
Dec  :: host---- mysqld[]: --  ::  [Note] Plugin 'FEEDBACK' is disabled.
Dec  :: host---- mysqld[]: --  ::  [Note] Server socket created on IP: '::'.
Dec  :: host---- mysqld[]: --  ::  [ERROR] 1
Dec  :: host---- mysqld[]: --  ::  [ERROR] Do you already have another mysqld server running ...:  ?
Dec  :: host---- mysqld[]: --  ::  [ERROR] Aborting
Dec  :: host---- systemd[]: mariadb.service: main process exited, code=exited, status=/FAILURE
Dec  :: host---- systemd[]: Failed to start MariaDB 10.2. database server.
Dec  :: host---- systemd[]: Unit mariadb.service entered failed state.
Dec  :: host---- systemd[]: mariadb.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

2：解决方法

修改mysql端口后需要修改： vi /etc/selinux/config
SELINUX=disabled
然后重启服务。
可以用命令：setenforce 0 临时关闭selinux ，不用重启服务器；
setenforce 0
systemctl restart mariadb