CentOS 7启动数据库服务失败

说明：记录一次启动数据库失败的异常

场景

powershell 复制代码

systemctl start mysqld

使用systemctl start mysqld命令启动MySQL服务，报下面的错误：

复制代码

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

提示让我使用journalctl -xe命令，查看一下详细，内容如下：

复制代码

4月 10 20:50:22 CentOS79 polkitd[848]: Unregistered Authentication Agent for unix-process:13016:187895386 (system bus name :1.1185, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale zh_CN.UTF-8) (disconnected from bus)
4月 10 20:50:42 CentOS79 polkitd[848]: Registered Authentication Agent for unix-process:13026:187897598 (system bus name :1.1186 [/usr/bin/pkttyagent --notify-fd 5 --fallback], object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale zh_CN.UTF-8)
4月 10 20:50:42 CentOS79 systemd[1]: Starting mysqld.service...
-- 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.
4月 10 20:50:45 CentOS79 systemd[1]: mysqld.service: control process exited, code=exited status=1
4月 10 20:50:45 CentOS79 systemd[1]: Failed to start mysqld.service.
-- 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.
4月 10 20:50:45 CentOS79 systemd[1]: Unit mysqld.service entered failed state.
4月 10 20:50:45 CentOS79 systemd[1]: mysqld.service failed.
4月 10 20:50:45 CentOS79 polkitd[848]: Unregistered Authentication Agent for unix-process:13026:187897598 (system bus name :1.1186, object path /org/freedesktop/PolicyKit1/AuthenticationAgent, locale zh_CN.UTF-8) (disconnected from bus)

毫无头绪，然后我查看了一下MySQL记录的日志信息，如下：

复制代码

2024-04-10T12:50:42.738859Z 0 [Warning] Changed limits: max_open_files: 5000 (requested 7500)
2024-04-10T12:50:42.738955Z 0 [Warning] Changed limits: table_open_cache: 1745 (requested 2048)
2024-04-10T12:50:42.917286Z 0 [Note] --secure-file-priv is set to NULL. Operations related to importing and exporting data are disabled
2024-04-10T12:50:42.917339Z 0 [Note] /data/mysql/bin/mysqld (mysqld 5.7.36-log) starting as process 13032 ...
2024-04-10T12:50:42.922551Z 0 [Note] InnoDB: PUNCH HOLE support available
2024-04-10T12:50:42.922590Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2024-04-10T12:50:42.922595Z 0 [Note] InnoDB: Uses event mutexes
2024-04-10T12:50:42.922598Z 0 [Note] InnoDB: GCC builtin __sync_synchronize() is used for memory barrier
2024-04-10T12:50:42.922602Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2024-04-10T12:50:42.922606Z 0 [Note] InnoDB: Using Linux native AIO
2024-04-10T12:50:42.923404Z 0 [Note] InnoDB: Number of pools: 1
2024-04-10T12:50:42.923536Z 0 [Note] InnoDB: Using CPU crc32 instructions
2024-04-10T12:50:42.925015Z 0 [Note] InnoDB: Initializing buffer pool, total size = 10G, instances = 8, chunk size = 128M
2024-04-10T12:50:43.486095Z 0 [Note] InnoDB: Completed initialization of buffer pool
2024-04-10T12:50:43.555443Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2024-04-10T12:50:43.567488Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2024-04-10T12:50:43.750980Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2024-04-10T12:50:43.751049Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2024-04-10T12:50:43.765705Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2024-04-10T12:50:43.766370Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2024-04-10T12:50:43.766378Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2024-04-10T12:50:43.767368Z 0 [Note] InnoDB: Waiting for purge to start
2024-04-10T12:50:43.817571Z 0 [Note] InnoDB: 5.7.36 started; log sequence number 2750697
2024-04-10T12:50:43.817969Z 0 [Note] InnoDB: Loading buffer pool(s) from /data/mydata/ib_buffer_pool
2024-04-10T12:50:43.818543Z 0 [Note] Plugin 'FEDERATED' is disabled.
2024-04-10T12:50:43.819940Z 0 [Note] InnoDB: Buffer pool(s) load completed at 240410 20:50:43
2024-04-10T12:50:43.824078Z 0 [ERROR] Too many arguments (first extra is 'start').
2024-04-10T12:50:43.824097Z 0 [Note] Use --verbose --help to get a list of available options!
2024-04-10T12:50:43.824103Z 0 [ERROR] Aborting

2024-04-10T12:50:43.824114Z 0 [Note] Binlog end
............
2024-04-10T12:50:45.650620Z 0 [Note] /data/mysql/bin/mysqld: Shutdown complete

有一条ERROR，[ERROR] Too many arguments (first extra is 'start').，于是我查了许多这方面的文章、博客，但都没有用；

解决

使用systemctl start mysql，即去掉最后一个d。我也不太清楚，前面的时候为什么要加上一个d，后面偶然漏敲了，反而可以正常启动。

powershell 复制代码

systemctl start mysql