Mysql 如何更改Mariadb 10.3的PID位置？

我正在使用centos7.3，通过

yum安装mariadb服务器mariadb客户端安装mariadb 10.3

在my.cnf中，我设置PID位置如下：

[mysqld_safe]
pid-file=/var/run/mariadb/mariadb.pid  

我可以登录到mariadb，并且error-log中没有错误。但是我找不到

/var/run/mariadb/mariadb.pid

即使我触摸

/var/run/mariadb/mariadb.pid

和

chown-mysql:mysql

，在

/var/run/mariadb/mariadb.pid

中也没有任何内容

根据olegsv的回答，PID位置是

/var/lib/mysql/localhost.PID

MariaDB [(none)]> show variables like '%pid%';
+---------------+------------------------------+
| Variable_name | Value                        |
+---------------+------------------------------+
| pid_file      | /var/lib/mysql/localhost.pid |
+---------------+------------------------------+
1 row in set (0.001 sec)  

根据Rick James的回答，我将

pid文件=/var/run/mariadb/mariadb.pid

移动到

[mysqld]

和

systemctl restart mariadb

，我发现mariadb无法重新启动，错误信息如下：

[root@localhost my.cnf.d]# systemctl status mariadb -l
● mariadb.service - MariaDB 10.3.10 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 Sun 2018-10-21 1:10:12 UTC; 30s ago
     Docs: man:mysqld(8)
           https://mariadb.com/kb/en/library/systemd/
  Process: 1502 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 1610 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=exited, status=1/FAILURE)
  Process: 1517 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`/usr/bin/galera_recovery`; [ $? -eq 0 ]   && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
  Process: 1515 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
 Main PID: 1610 (code=exited, status=1/FAILURE)

Oct 21 1:10:12 localhost.localdomain systemd[1]: Starting MariaDB 10.3.10 database server...
Oct 21 1:10:12 localhost.localdomain mysqld[1610]: 2018-10-21 1:10:12 0 [Note] /usr/sbin/mysqld (mysqld 10.3.10-MariaDB-log) starting as process 1610 ...
Oct 21 1:10:12 localhost.localdomain systemd[1]: mariadb.service: main process exited, code=exited, status=1/FAILURE
Oct 21 1:10:12 localhost.localdomain systemd[1]: Failed to start MariaDB 10.3.10 database server.
Oct 21 1:10:12 localhost.localdomain systemd[1]: Unit mariadb.service entered failed state.
Oct 21 1:10:12 localhost.localdomain systemd[1]: mariadb.service failed.  

以及：

[root@localhost my.cnf.d]# journalctl -xe
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mariadb.service has begun shutting down.
Oct 21 1:10:12 localhost.localdomain systemd[1]: Starting MariaDB 10.3.10 datab
-- Subject: Unit mariadb.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mariadb.service has begun starting up.
Oct 21 1:10:12 localhost.localdomain mysqld[1610]: 2018-10-21 1:10:12 0 [Note]
Oct 21 1:10:12 localhost.localdomain systemd[1]: mariadb.service: main process
Oct 21 1:10:12 localhost.localdomain systemd[1]: Failed to start MariaDB 10.3.1
-- Subject: Unit mariadb.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mariadb.service has failed.
--
-- The result is failed.
Oct 21 1:10:12 localhost.localdomain systemd[1]: Unit mariadb.service entered f
Oct 21 1:10:12 localhost.localdomain systemd[1]: mariadb.service failed.
Oct 21 1:10:12 localhost.localdomain polkitd[601]: Unregistered Authentication

---

如何更改Mariadb 10.3的PID位置？

从Mariadb客户端提示符：

show variables like '%pid%';

在

my.cnf

（或配置文件所在的位置）中，添加

[mysqld]

部分：

pid-file = /path/to/filename

---

在这个问题中，

pid文件=/var/run/mariadb/mariadb.pid

不起作用，有什么原因吗？你的意思是我应该使用

pit文件而不是
pid文件
？确保它在
[mysqld]
节中。在[mysqld]节中会导致mariadb无法重新启动，我不理解原因。我发布了有问题的错误信息。我只修改了
/etc/my.conf.d/server.cnf
，上传这个文件，让我们用另一种方式处理它。。。为什么“需要”更改pid位置？@RickJames，至少，我需要找出pid与设置不同的原因。