Can'；在RHEL升级到7.2，未注册的身份验证代理后，不要启动MySQL

我刚刚将RHEL系统从

6.7

升级到

7.2

，再次启动MySQL时遇到问题

运行时：

# systemctl start mysqld

我得到这个错误：

Job for mysqld.service failed because the control process exited with error code. 
See "systemctl status mysqld.service" and "journalctl -xe" for details.

systemctl status

告诉我以下信息：

● mysqld.service - SYSV: MySQL database server.
   Loaded: loaded (/etc/rc.d/init.d/mysqld)
   Active: failed (Result: exit-code) since Tue 2017-05-02 10:00:52 CDT; 59s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 21827 ExecStart=/etc/rc.d/init.d/mysqld start (code=exited, status=1/FAILURE)

May 02 10:00:51 sa-dnca01.zs.local systemd[1]: Starting SYSV: MySQL database server....
May 02 10:00:52 sa-dnca01.zs.local mysqld[21827]: MySQL Daemon failed to start.
May 02 10:00:52 sa-dnca01.zs.local mysqld[21827]: Starting mysqld:  [FAILED]
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: mysqld.service: control process exited, code=exited status=1
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: Failed to start SYSV: MySQL database server..
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: Unit mysqld.service entered failed state.
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: mysqld.service failed.

May 02 10:03:09 sa-dnca01.zs.local polkitd[768]: Registered Authentication Agent for unix-process:22276:29249716 (system bus name :1.30 [/usr/bin/
May 02 10:03:09 sa-dnca01.zs.local systemd[1]: Starting SYSV: MySQL database server....
-- Subject: Unit mysqld.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has begun starting up.
May 02 10:03:10 sa-dnca01.zs.local mysqld[22281]: MySQL Daemon failed to start.
May 02 10:03:10 sa-dnca01.zs.local mysqld[22281]: Starting mysqld:  [FAILED]
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: mysqld.service: control process exited, code=exited status=1
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: Failed to start SYSV: MySQL database server..
-- Subject: Unit mysqld.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has failed.
--
-- The result is failed.
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: Unit mysqld.service entered failed state.
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: mysqld.service failed.
May 02 10:03:10 sa-dnca01.zs.local polkitd[768]: Unregistered Authentication Agent for unix-process:22276:29249716 (system bus name :1.30, object

然后，

journalctl-xe

告诉我：

● mysqld.service - SYSV: MySQL database server.
   Loaded: loaded (/etc/rc.d/init.d/mysqld)
   Active: failed (Result: exit-code) since Tue 2017-05-02 10:00:52 CDT; 59s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 21827 ExecStart=/etc/rc.d/init.d/mysqld start (code=exited, status=1/FAILURE)

May 02 10:00:51 sa-dnca01.zs.local systemd[1]: Starting SYSV: MySQL database server....
May 02 10:00:52 sa-dnca01.zs.local mysqld[21827]: MySQL Daemon failed to start.
May 02 10:00:52 sa-dnca01.zs.local mysqld[21827]: Starting mysqld:  [FAILED]
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: mysqld.service: control process exited, code=exited status=1
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: Failed to start SYSV: MySQL database server..
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: Unit mysqld.service entered failed state.
May 02 10:00:52 sa-dnca01.zs.local systemd[1]: mysqld.service failed.

May 02 10:03:09 sa-dnca01.zs.local polkitd[768]: Registered Authentication Agent for unix-process:22276:29249716 (system bus name :1.30 [/usr/bin/
May 02 10:03:09 sa-dnca01.zs.local systemd[1]: Starting SYSV: MySQL database server....
-- Subject: Unit mysqld.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has begun starting up.
May 02 10:03:10 sa-dnca01.zs.local mysqld[22281]: MySQL Daemon failed to start.
May 02 10:03:10 sa-dnca01.zs.local mysqld[22281]: Starting mysqld:  [FAILED]
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: mysqld.service: control process exited, code=exited status=1
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: Failed to start SYSV: MySQL database server..
-- Subject: Unit mysqld.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has failed.
--
-- The result is failed.
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: Unit mysqld.service entered failed state.
May 02 10:03:10 sa-dnca01.zs.local systemd[1]: mysqld.service failed.
May 02 10:03:10 sa-dnca01.zs.local polkitd[768]: Unregistered Authentication Agent for unix-process:22276:29249716 (system bus name :1.30, object

---

我真的不知道这意味着什么，但在MySQL服务器升级操作系统之前，我确实有一个成功运行的MySQL服务器

原来我收到这个错误是因为我没有在中创建必要的日志目录：

/var/run/mysqld

并授予它适当的权限

查看

/var/log/mysqld.log

中的日志文件，我发现了这个问题