1、service mysqld start? ?启动mysql
Redirecting to /bin/systemctl start mysqld.service
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
?通过?systemctl status mysqld.service 或者 journalctl -xe命令查看具体报错原因
mysql的配置文件地址?vim /etc/my.cnf 查看日志文件具体地址
?log-error=/var/log/mysqld.log，我的日志是存在这了，打开日志看个究竟。
最后面能看到这么一大坨的东西，看下日志时间相差了8小时，这是因为我没有去配置时区，当然这个不是重点。
2019-05-15T01:08:24.682793Z 0 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX'
2019-05-15T01:08:24.682795Z 0 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET'
2019-05-15T01:08:24.682797Z 0 [Note] Shutting down plugin 'INNODB_CMPMEM'
2019-05-15T01:08:24.682799Z 0 [Note] Shutting down plugin 'INNODB_CMP_RESET'
2019-05-15T01:08:24.682800Z 0 [Note] Shutting down plugin 'INNODB_CMP'
2019-05-15T01:08:24.682802Z 0 [Note] Shutting down plugin 'INNODB_LOCK_WAITS'
2019-05-15T01:08:24.682804Z 0 [Note] Shutting down plugin 'INNODB_LOCKS'
2019-05-15T01:08:24.682806Z 0 [Note] Shutting down plugin 'INNODB_TRX'
2019-05-15T01:08:24.682807Z 0 [Note] Shutting down plugin 'InnoDB'
2019-05-15T01:08:24.684767Z 0 [Note] InnoDB: FTS optimize thread exiting.
2019-05-15T01:08:24.684867Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2019-05-15T01:08:24.684972Z 0 [Note] InnoDB: Buffer pool(s) load completed at 190515 ?9:08:24
2019-05-15T01:08:24.685009Z 0 [Note] InnoDB: Starting shutdown...
2019-05-15T01:08:24.785342Z 0 [Note] InnoDB: Dumping buffer pool(s) to /var/lib/mysql/ib_buffer_pool
2019-05-15T01:08:24.785563Z 0 [Note] InnoDB: Buffer pool(s) dump completed at 190515 ?9:08:24
里面也没啥关键信息，这么多看起来贼烦，我们来过滤下。
执行 ? tail -n500 /var/log/mysqld.log|grep -E 'Warning|ERROR'
2019-05-15T01:12:38.934502Z 0 [ERROR] unknown variable 'binlog_fromat=mixed'
2019-05-15T01:12:38.934522Z 0 [ERROR] Aborting
2019-05-15T01:12:40.984590Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-05-15T01:12:41.188849Z 0 [ERROR] unknown variable 'binlog_fromat=mixed'
2019-05-15T01:12:41.188873Z 0 [ERROR] Aborting
2019-05-15T01:12:43.228937Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-05-15T01:12:43.431933Z 0 [ERROR] unknown variable 'binlog_fromat=mixed'
2019-05-15T01:12:43.431951Z 0 [ERROR] Aborting
到这里就很明显能看出问题了，提示未知参数，我们的英文单词拼错了。你问我怎么会敲错的，因为是信了网上亲测可用的这些帖子的邪了。这要是可用我把小牛子都给你揪下来。
?
2、我的问题是磁盘不足
?3、通过?du -sh *|sort -n 查看当前目录磁盘占用情况，处理磁盘不足问题