本来mysql好的，之前清理了一次tmp下的东西，mysql在查询的时候提示：
Can‘t create/write to file ‘/tmp/ib0n3frL
然后停止启动：
[root@sevck_linux mysql]# service mysqld start
MySQL Daemon failed to start.
Starting mysqld: [FAILED]
启动失败了，看一下日志，发现配置的时候没添加日志配置
查找my.cnf,在[mysqld]下添加log-error=/var/log/mysql/mysql-error.log
配置mysql的错误日志，mysql目录自行设置，其中记住一点，chown -R mysql:mysql /tmp/mysql
赋予mysql目录权限，因为我是root, mysql运行权限为mysql，没有权限
再启动mysql尝试：
180222 10:45:28 InnoDB: Mutexes and rw_locks use GCC atomic builtins 180222 10:45:28 InnoDB: Compressed tables use zlib 1.2.3 180222 10:45:28 InnoDB: Using Linux native AIO ^G/usr/libexec/mysqld: Can‘t create/write to file ‘/tmp/mysql_data/ibAGn543‘ (Errcode: 13) 180222 10:45:28 InnoDB: Error: unable to create temporary file; errno: 13 180222 10:45:28 [ERROR] Plugin ‘InnoDB‘ init function returned error. 180222 10:45:28 [ERROR] Plugin ‘InnoDB‘ registration as a STORAGE ENGINE failed. 180222 10:45:28 [ERROR] Unknown/unsupported storage engine: InnoDB 180222 10:45:28 [ERROR] Aborting 180222 10:45:28 [Note] /usr/libexec/mysqld: Shutdown complete
原来是Can‘t create/write to file，那么就好解决了，看看mysql_data目录是否存在。
chmod -R 777 /tmp
赋予写的权限，启动mysql:
root@sevck_linux mysql]# service mysqld start
Starting mysqld: [ OK ]
just do it.